From e457a124e1661f3d717fe7394a447d1f4faecca8 Mon Sep 17 00:00:00 2001
From: TMHSDigital <154358121+TMHSDigital@users.noreply.github.com>
Date: Sun, 13 Sep 2026 10:27:25 -0400
Subject: [PATCH 1/2] feat: add CLI falsifiers and exit tables to the remaining
 twelve examples

Closes the last behavior gap in the retrofit: every example now has a flag that
makes an existing assertion fail, without touching Grease Pencil version shims
or changing any exit code value.

Signed-off-by: TMHSDigital <154358121+TMHSDigital@users.noreply.github.com>
Co-authored-by: Cursor <cursoragent@cursor.com>
---
 examples/compositor-glare/README.md           | 24 +++++++++++--
 examples/compositor-glare/compositor_glare.py | 14 ++++++--
 examples/curve-bevel-arc/README.md            | 28 +++++++++++++--
 examples/curve-bevel-arc/curve_bevel_arc.py   | 14 ++++++--
 examples/gp-lineart-contour/README.md         | 26 ++++++++++++--
 .../gp-lineart-contour/gp_lineart_contour.py  | 14 ++++++++
 examples/grease-pencil-rosette/README.md      | 27 ++++++++++++--
 .../grease_pencil_rosette.py                  | 19 +++++++---
 examples/light-link-studio/README.md          | 27 ++++++++++++--
 .../light-link-studio/light_link_studio.py    | 13 +++++--
 examples/png-exr-alpha/README.md              | 31 +++++++++++++---
 examples/png-exr-alpha/png_exr_alpha.py       | 24 ++++++++-----
 examples/shader-node-group/README.md          | 25 +++++++++++--
 .../shader-node-group/shader_node_group.py    | 15 ++++++--
 examples/sky-texture-sun-elevation/README.md  | 26 ++++++++++++--
 .../sky_texture_sun_elevation.py              | 19 ++++++++--
 examples/text-version-stamp/README.md         | 35 +++++++++++++++----
 .../text-version-stamp/text_version_stamp.py  | 18 +++++++---
 examples/turntable/README.md                  | 26 ++++++++++++--
 examples/turntable/turntable.py               | 22 ++++++++----
 examples/vse-cut-list/README.md               | 33 ++++++++++++++---
 examples/vse-cut-list/vse_cut_list.py         | 18 ++++++++--
 examples/vse-gamma-cross/README.md            | 26 ++++++++++++--
 examples/vse-gamma-cross/vse_gamma_cross.py   | 17 ++++++---
 24 files changed, 454 insertions(+), 87 deletions(-)

diff --git a/examples/compositor-glare/README.md b/examples/compositor-glare/README.md
index 373b2c7..94db31c 100644
--- a/examples/compositor-glare/README.md
+++ b/examples/compositor-glare/README.md
@@ -29,11 +29,29 @@ absence of any EEVEE bloom toggle.
 # Cheap correctness check (two tiny renders) — the CI check:
 blender --background --python compositor_glare.py --
 
+# Falsifier: Threshold=10.0. Must exit non-zero (Threshold==1.0).
+blender --background --python compositor_glare.py -- --threshold-high
+
 # Also render a still (EEVEE on a GPU host; use --engine cycles on GPU-less hosts):
 blender --background --python compositor_glare.py -- --output rings.png
 blender --background --python compositor_glare.py -- --output rings.png --engine cycles
 ```
 
-It exits non-zero on failure (wrong tree plumbing, wrong Glare configuration, a
-missing or non-falling halo, or halo pixels that appear without the compositor).
-The `blender-smoke` workflow runs the check on Blender 5.2 LTS and 4.5 LTS.
+## Exit codes
+
+Per-script sequential checks. `9` is a valid check code; there is no rule
+against it.
+
+| Code | Meaning |
+| --- | --- |
+| 0 | Success |
+| 1 | Uncaught exception (FATAL wrapper) |
+| 2 | argparse / usage |
+| 3 | Compositor tree / Glare / Threshold / link-chain contract (`--threshold-high` lands here) |
+| 4 | Check render missing, tube dark, no halo, or halo does not fall off |
+| 5 | Halo present with compositing off |
+| 6 | `--output` produced no file |
+
+The `blender-smoke` workflow runs the check on Blender 5.2 LTS and 4.5 LTS
+(5.1 on the weekly cron, the `needs-5.1` PR label, or manual dispatch).
+Smoke does not pass `--output` or `--threshold-high`.
diff --git a/examples/compositor-glare/compositor_glare.py b/examples/compositor-glare/compositor_glare.py
index da94046..e78dc42 100644
--- a/examples/compositor-glare/compositor_glare.py
+++ b/examples/compositor-glare/compositor_glare.py
@@ -17,12 +17,17 @@
   the ring silhouette, falls off strictly with distance, and vanishes entirely
   when `scene.render.use_compositing` is off.
 
+``--threshold-high`` sets the shared ``Threshold`` input to 10.0 and still
+asserts it equals 1.0. That is the falsifier (``--same-axis`` in
+export-preset-axis). The 4.x/5.x Type-menu shim is untouched.
+
 By default it runs only the correctness check (two 96x54 single-sample Cycles
 renders, compositor on vs off) — the CI smoke check. Pass --output to also
 render a still:
 
-    blender --background --python compositor_glare.py --                 # check only
-    blender --background --python compositor_glare.py -- --output n.png  # + render
+    blender --background --python compositor_glare.py --                   # check only
+    blender --background --python compositor_glare.py -- --threshold-high   # must fail
+    blender --background --python compositor_glare.py -- --output n.png    # + render
 """
 import bpy
 import sys
@@ -337,9 +342,14 @@ def main():
                    help="render engine for --output (cycles for GPU-less hosts)")
     p.add_argument("--samples", type=int, default=32, help="--output sample count")
     p.add_argument("--width", type=int, default=1280, help="--output width; height is width*9/16")
+    p.add_argument("--threshold-high", action="store_true",
+                   help="falsifier: Threshold=10.0, still assert Threshold==1.0")
     args = p.parse_args(argv)
 
     scene, tree, glare = build_scene()
+    if args.threshold_high:
+        glare.inputs['Threshold'].default_value = 10.0
+
     code = check_structure(scene, tree, glare)
     if code:
         return code
diff --git a/examples/curve-bevel-arc/README.md b/examples/curve-bevel-arc/README.md
index b9aff28..0958899 100644
--- a/examples/curve-bevel-arc/README.md
+++ b/examples/curve-bevel-arc/README.md
@@ -17,12 +17,34 @@ and that the depsgraph-evaluated mesh has the deterministic topology (1044 verts
 # Cheap correctness check (no render) — the CI check:
 blender --background --python curve_bevel_arc.py --
 
+# Falsifier: uncapped tube. Must exit non-zero (use_fill_caps).
+blender --background --python curve_bevel_arc.py -- --no-caps
+
 # Also render a still (EEVEE on a GPU host; use --engine cycles on GPU-less hosts):
 blender --background --python curve_bevel_arc.py -- --output arc.png
 blender --background --python curve_bevel_arc.py -- --output arc.png --engine cycles
 ```
 
-It exits non-zero on failure (wrong point count, bevel, caps, topology, or span).
-The `blender-smoke` workflow runs the check on Blender 5.2 LTS and 4.5 LTS.
+## Exit codes
+
+Per-script sequential checks. `9` is a valid check code; there is no rule
+against it. `10` is also the shared framing helper.
+
+| Code | Meaning |
+| --- | --- |
+| 0 | Success |
+| 1 | Uncaught exception (FATAL wrapper) |
+| 2 | argparse / usage |
+| 3 | Spline type is not BEZIER |
+| 4 | Bezier point count ≠ 8 |
+| 5 | `bevel_depth` ≠ 0.15 |
+| 6 | `use_fill_caps` is False (`--no-caps` lands here) |
+| 7 | Evaluated vert/face count off measured tessellation |
+| 8 | Tube does not rest on the floor |
+| 9 | Tube height ≠ 2 × bevel |
+| 10 | X span off closed form; also gallery framing violation |
+| 11 | `--output` produced no file |
 
-The `--output` render path additionally measures framing against the Layer 1 band via `examples/gallery_framing.py` (exit 10 on violation) before writing the still.
+The `blender-smoke` workflow runs the check on Blender 5.2 LTS and 4.5 LTS
+(5.1 on the weekly cron, the `needs-5.1` PR label, or manual dispatch).
+Smoke does not pass `--output` or `--no-caps`.
diff --git a/examples/curve-bevel-arc/curve_bevel_arc.py b/examples/curve-bevel-arc/curve_bevel_arc.py
index 2046059..9041007 100644
--- a/examples/curve-bevel-arc/curve_bevel_arc.py
+++ b/examples/curve-bevel-arc/curve_bevel_arc.py
@@ -9,10 +9,14 @@
 has no simple closed form, so those two constants pin today's behavior (see
 EXPECT_VERTS below for how to re-measure if a future Blender retessellates).
 
+``--no-caps`` leaves ``use_fill_caps`` False and still asserts the ends are
+capped. That is the falsifier (``--same-axis`` in export-preset-axis).
+
 By default it runs only the correctness check (no render) — the CI smoke
 check. Pass --output to also render a still:
 
     blender --background --python curve_bevel_arc.py --                 # check only
+    blender --background --python curve_bevel_arc.py -- --no-caps       # must fail
     blender --background --python curve_bevel_arc.py -- --output c.png  # + render
 """
 import bpy, bmesh, sys, os, math, argparse
@@ -35,14 +39,15 @@
 EXPECT_FACES = 1028
 
 
-def build():
+def build(no_caps=False):
     bpy.ops.wm.read_factory_settings(use_empty=True)
     curve = bpy.data.curves.new("Arc", 'CURVE')
     curve.dimensions = '3D'
     curve.bevel_depth = BEVEL
     curve.bevel_resolution = BEVEL_RES
     curve.resolution_u = RES_U
-    curve.use_fill_caps = True  # solid ends — not a hollow pipe
+    curve.use_fill_caps = not no_caps  # solid ends — not a hollow pipe
+
 
     spline = curve.splines.new('BEZIER')
     spline.bezier_points.add(N_POINTS - 1)  # one point exists already
@@ -231,9 +236,12 @@ def main():
     p.add_argument("--output", default=None, help="optional: render a still PNG here")
     p.add_argument("--engine", default="eevee", choices=("eevee", "cycles"),
                    help="render engine for --output (cycles for GPU-less hosts)")
+    p.add_argument("--no-caps", action="store_true",
+                   help="falsifier: use_fill_caps=False, still assert caps")
     args = p.parse_args(argv)
 
-    obj = build()
+    obj = build(no_caps=args.no_caps)
+
     code = check(obj)
     if code:
         return code
diff --git a/examples/gp-lineart-contour/README.md b/examples/gp-lineart-contour/README.md
index a063dfc..ada7872 100644
--- a/examples/gp-lineart-contour/README.md
+++ b/examples/gp-lineart-contour/README.md
@@ -36,11 +36,31 @@ not zeroing strokes (exit 6), flags-off or restore failure (exit 7).
 # Depsgraph contour check — the CI check:
 blender --background --python gp_lineart_contour.py --
 
+# Falsifier: use_contour off. Must exit non-zero.
+blender --background --python gp_lineart_contour.py -- --no-contour
+
 # Also render the gallery still:
 blender --background --python gp_lineart_contour.py -- --output lineart.png
 ```
 
-It exits non-zero on failure. The `blender-smoke` workflow runs the check on
-Blender 5.2 LTS and 4.5 LTS.
+## Exit codes
+
+Per-script sequential checks. `9` is a valid check code; there is no rule
+against it. `10` is the shared framing helper.
+
+| Code | Meaning |
+| --- | --- |
+| 0 | Success |
+| 1 | Uncaught exception (FATAL wrapper) |
+| 2 | argparse / usage; also GPv3 collection address contract |
+| 3 | LINEART `thickness` / `radius` trap for this Blender |
+| 4 | LINEART type, source, or `use_contour` (`--no-contour` lands here) |
+| 5 | Evaluated contour too thin |
+| 6 | Cleared `source_object` still produced strokes |
+| 7 | Contour+crease off still produced strokes, or restore failed |
+| 8 | `--output` produced no file |
+| 10 | Gallery framing violation |
 
-The `--output` render path additionally measures framing against the Layer 1 band via `examples/gallery_framing.py` (exit 10 on violation) before writing the still.
+The `blender-smoke` workflow runs the check on Blender 5.2 LTS and 4.5 LTS
+(5.1 on the weekly cron, the `needs-5.1` PR label, or manual dispatch).
+Smoke does not pass `--output` or `--no-contour`.
diff --git a/examples/gp-lineart-contour/gp_lineart_contour.py b/examples/gp-lineart-contour/gp_lineart_contour.py
index f155cad..631ea30 100644
--- a/examples/gp-lineart-contour/gp_lineart_contour.py
+++ b/examples/gp-lineart-contour/gp_lineart_contour.py
@@ -17,9 +17,15 @@
 The check evaluates the modifier through the depsgraph (no bake required)
 and asserts stroke/point lower bounds against the known failure modes above.
 
+``--no-contour`` clears ``use_contour`` after the modifier is built and
+still asserts it is True. That is the falsifier (``--same-axis`` in
+export-preset-axis). The GPv3 address shim and the thickness/radius trap
+are untouched.
+
 By default it runs the correctness check only. Pass --output to render:
 
     blender --background --python gp_lineart_contour.py --
+    blender --background --python gp_lineart_contour.py -- --no-contour
     blender --background --python gp_lineart_contour.py -- --output l.png
 """
 import bpy, bmesh, sys, os, math, argparse
@@ -415,10 +421,18 @@ def main():
         choices=("eevee", "cycles"),
         help="render engine for --output",
     )
+    p.add_argument(
+        "--no-contour",
+        action="store_true",
+        help="falsifier: use_contour=False, still assert True",
+    )
     args = p.parse_args(argv)
 
     print(f"binary version: {bpy.app.version} ({bpy.app.version_string})")
     sc, crystal, la_ob, mod = build_scene()
+    if args.no_contour:
+        mod.use_contour = False
+
     code = check(sc, crystal, la_ob, mod)
     if code:
         return code
diff --git a/examples/grease-pencil-rosette/README.md b/examples/grease-pencil-rosette/README.md
index 615fa0d..2cc8ed0 100644
--- a/examples/grease-pencil-rosette/README.md
+++ b/examples/grease-pencil-rosette/README.md
@@ -27,11 +27,32 @@ raw `position` attribute buffer via `foreach_get`.
 # Cheap correctness check (no render) — the CI check:
 blender --background --python grease_pencil_rosette.py --
 
+# Falsifier: open strokes. Must exit non-zero (cyclic).
+blender --background --python grease_pencil_rosette.py -- --open-strokes
+
 # Also render a still (EEVEE on a GPU host; use --engine cycles on GPU-less hosts):
 blender --background --python grease_pencil_rosette.py -- --output rosette.png
 blender --background --python grease_pencil_rosette.py -- --output rosette.png --engine cycles
 ```
 
-It exits non-zero on failure (wrong version gate, structural mismatch, missing attribute
-layers, or attribute-buffer deviation from the closed form). The `blender-smoke` workflow
-runs the check on Blender 5.2 LTS and 4.5 LTS.
+## Exit codes
+
+Per-script sequential checks. `9` is a valid check code; there is no rule
+against it.
+
+| Code | Meaning |
+| --- | --- |
+| 0 | Success |
+| 1 | Uncaught exception (FATAL wrapper) |
+| 2 | argparse / usage |
+| 3 | GPv3 address / legacy trap for this Blender |
+| 4 | Object type, layer count, or frame number |
+| 5 | Stroke topology or cyclic (`--open-strokes` lands here) |
+| 6 | Lazy attribute layers missing or wrong domain/type |
+| 7 | Position buffer length or closed-form round-trip |
+| 8 | Grease Pencil material missing gpencil settings |
+| 9 | `--output` produced no file |
+
+The `blender-smoke` workflow runs the check on Blender 5.2 LTS and 4.5 LTS
+(5.1 on the weekly cron, the `needs-5.1` PR label, or manual dispatch).
+Smoke does not pass `--output` or `--open-strokes`.
diff --git a/examples/grease-pencil-rosette/grease_pencil_rosette.py b/examples/grease-pencil-rosette/grease_pencil_rosette.py
index 8198404..6114288 100644
--- a/examples/grease-pencil-rosette/grease_pencil_rosette.py
+++ b/examples/grease-pencil-rosette/grease_pencil_rosette.py
@@ -19,11 +19,16 @@
 materialization, and a closed-form round-trip of every position through the
 raw POINT attribute buffer.
 
+``--open-strokes`` leaves every stroke non-cyclic and still asserts they
+are cyclic. That is the falsifier (``--same-axis`` in export-preset-axis).
+The GPv3 address shim is untouched.
+
 By default it runs only the correctness check (no render) — the CI smoke
 check. Pass --output to also render a still:
 
-    blender --background --python grease_pencil_rosette.py --                # check only
-    blender --background --python grease_pencil_rosette.py -- --output r.png # + render
+    blender --background --python grease_pencil_rosette.py --                  # check only
+    blender --background --python grease_pencil_rosette.py -- --open-strokes   # must fail
+    blender --background --python grease_pencil_rosette.py -- --output r.png   # + render
 """
 import bpy, sys, os, math, argparse, colorsys
 
@@ -66,7 +71,7 @@ def gp_data_new(name):
     return bpy.data.grease_pencils_v3.new(name)       # 4.5 LTS: GPv3 lives at _v3
 
 
-def build_rosette():
+def build_rosette(open_strokes=False):
     bpy.ops.wm.read_factory_settings(use_empty=True)
     gp = gp_data_new("Rosette")
     layer = gp.layers.new("Ink")
@@ -75,8 +80,9 @@ def build_rosette():
 
     drawing.add_strokes([POINTS] * RINGS)
     for ring, stroke in enumerate(drawing.strokes):
-        stroke.cyclic = True
+        stroke.cyclic = not open_strokes
         for i, pt in enumerate(stroke.points):
+
             pt.position = rose_point(ring, i)
             pt.radius = point_radius(ring, i)
             pt.opacity = 1.0
@@ -267,9 +273,12 @@ def main():
     p.add_argument("--output", default=None, help="optional: render a still PNG here")
     p.add_argument("--engine", default="eevee", choices=("eevee", "cycles"),
                    help="render engine for --output (cycles for GPU-less hosts)")
+    p.add_argument("--open-strokes", action="store_true",
+                   help="falsifier: strokes not cyclic, still assert cyclic")
     args = p.parse_args(argv)
 
-    obj = build_rosette()
+    obj = build_rosette(open_strokes=args.open_strokes)
+
     code = check(obj)
     if code:
         return code
diff --git a/examples/light-link-studio/README.md b/examples/light-link-studio/README.md
index 677a7b6..1dc06ff 100644
--- a/examples/light-link-studio/README.md
+++ b/examples/light-link-studio/README.md
@@ -53,10 +53,31 @@ pool raking the wall behind them — one key, one hero.
 # Two-render correctness check (tiny Cycles CPU renders) — the CI check:
 blender --background --python light_link_studio.py --
 
+# Falsifier: receiver_collection unset. Must exit non-zero (assignment).
+blender --background --python light_link_studio.py -- --skip-link
+
 # Also render the gallery still (Cycles, deterministic samples):
 blender --background --python light_link_studio.py -- --output linked.png
 ```
 
-It exits non-zero on failure (API moved, assignment lost, ratio below gate,
-insufficient unlink rise, or hero drift). The `blender-smoke` workflow runs
-the check on Blender 5.2 LTS and 4.5 LTS.
+## Exit codes
+
+Per-script sequential checks. `9` is a valid check code; there is no rule
+against it.
+
+| Code | Meaning |
+| --- | --- |
+| 0 | Success |
+| 1 | Uncaught exception (FATAL wrapper) |
+| 2 | argparse / usage |
+| 3 | Light datablock gained `light_linking` |
+| 4 | Light objects lost `light_linking` |
+| 5 | `receiver_collection` assignment did not read back (`--skip-link` lands here) |
+| 6 | Linked state: hero dark or hero/decoy ratio below gate |
+| 7 | Decoy rise below gate when unlinked |
+| 8 | Hero drifted across the unlink |
+| 9 | `--output` produced no file |
+
+The `blender-smoke` workflow runs the check on Blender 5.2 LTS and 4.5 LTS
+(5.1 on the weekly cron, the `needs-5.1` PR label, or manual dispatch).
+Smoke does not pass `--output` or `--skip-link`.
diff --git a/examples/light-link-studio/light_link_studio.py b/examples/light-link-studio/light_link_studio.py
index 9e82368..3ef7614 100644
--- a/examples/light-link-studio/light_link_studio.py
+++ b/examples/light-link-studio/light_link_studio.py
@@ -20,10 +20,14 @@
 4.5 LTS and 5.1 (ObjectLightLinking with
 receiver_collection/blocker_collection on both).
 
+``--skip-link`` leaves ``receiver_collection`` unset and still asserts the
+hero collection. That is the falsifier (``--same-axis`` in export-preset-axis).
+
 By default it runs the two-render correctness check (no gallery still) — the
 CI smoke check. Pass --output to also render a still:
 
     blender --background --python light_link_studio.py --                 # check only
+    blender --background --python light_link_studio.py -- --skip-link     # must fail
     blender --background --python light_link_studio.py -- --output l.png  # + render
 """
 import bpy, bmesh, sys, os, math, argparse, tempfile, shutil
@@ -288,7 +292,7 @@ def render_lumas(sc, tmp, name, hero, decoy):
     return out[0], out[1]
 
 
-def check(sc, key, hero_c, hero, decoy):
+def check(sc, key, hero_c, hero, decoy, skip_link=False):
     # contract 0 (RNA guard): the API is on the light OBJECT
     ld = key.data
     if hasattr(ld, "light_linking"):
@@ -300,7 +304,7 @@ def check(sc, key, hero_c, hero, decoy):
         return 4
 
     # contract 1 (assignment round-trip through the API itself)
-    key.light_linking.receiver_collection = hero_c
+    key.light_linking.receiver_collection = None if skip_link else hero_c
     if key.light_linking.receiver_collection != hero_c:
         print("ERROR: receiver_collection assignment did not read back",
               file=sys.stderr)
@@ -398,12 +402,15 @@ def main():
     argv = sys.argv[sys.argv.index("--") + 1:] if "--" in sys.argv else []
     p = argparse.ArgumentParser()
     p.add_argument("--output", default=None, help="optional: render a still PNG here")
+    p.add_argument("--skip-link", action="store_true",
+                   help="falsifier: leave receiver_collection unset, still assert hero_c")
     args = p.parse_args(argv)
 
     bpy.ops.wm.read_factory_settings(use_empty=True)
     sc = bpy.context.scene
     hero, decoy, hero_c, key = build_studio(sc)
-    code = check(sc, key, hero_c, hero, decoy)
+    code = check(sc, key, hero_c, hero, decoy, skip_link=args.skip_link)
+
     if code:
         return code
 
diff --git a/examples/png-exr-alpha/README.md b/examples/png-exr-alpha/README.md
index 4895b56..446b4a4 100644
--- a/examples/png-exr-alpha/README.md
+++ b/examples/png-exr-alpha/README.md
@@ -63,13 +63,36 @@ contract failed, both panels would read the same.
 # Cheap correctness check (no render) — the CI check:
 blender --background --python png_exr_alpha.py --
 
+# Falsifier: opaque authored alpha. Must exit non-zero (float→PNG error floor).
+blender --background --python png_exr_alpha.py -- --opaque-alpha
+
 # Also render a still (EEVEE on a GPU host; use --engine cycles on GPU-less hosts):
 blender --background --python png_exr_alpha.py -- --output alpha.png
 blender --background --python png_exr_alpha.py -- --output alpha.png --engine cycles
 ```
 
-It exits non-zero on failure and prints every measured error and tolerance on
-success, so CI logs carry the numbers. The `blender-smoke` workflow runs the
-check on Blender 5.2 LTS and 4.5 LTS.
+## Exit codes
+
+Per-script sequential checks. `9` is a valid check code; there is no rule
+against it. `10` is also the shared framing helper.
+
+| Code | Meaning |
+| --- | --- |
+| 0 | Success |
+| 1 | Uncaught exception (FATAL wrapper) |
+| 2 | argparse / usage; also closed-form palette no longer stresses unpremul |
+| 3 | `float_buffer=True` image reports `is_float=False` |
+| 4 | Float→PNG IHDR is not RGBA16 |
+| 5 | Float→PNG RGB error below floor (`--opaque-alpha` lands here) |
+| 6 | Float→PNG disagrees with closed-form false-unpremul model |
+| 7 | Float→EXR round-trip above tolerance |
+| 8 | `float_buffer=False` image reports `is_float=True` |
+| 9 | Byte→PNG IHDR is not RGBA8 |
+| 10 | Byte→PNG disagrees with straight-alpha 8-bit model; also gallery framing violation |
+| 11 | Byte→PNG stress cell looks false-unpremul-mangled |
+| 12 | EXR `color_mode=RGB` alpha-drop contract |
+| 13 | `--output` produced no file |
 
-The `--output` render path additionally measures framing against the Layer 1 band via `examples/gallery_framing.py` (exit 10 on violation) before writing the still.
+The `blender-smoke` workflow runs the check on Blender 5.2 LTS and 4.5 LTS
+(5.1 on the weekly cron, the `needs-5.1` PR label, or manual dispatch).
+Smoke does not pass `--output` or `--opaque-alpha`.
diff --git a/examples/png-exr-alpha/png_exr_alpha.py b/examples/png-exr-alpha/png_exr_alpha.py
index f9b961d..d041dcc 100644
--- a/examples/png-exr-alpha/png_exr_alpha.py
+++ b/examples/png-exr-alpha/png_exr_alpha.py
@@ -10,11 +10,14 @@
 with straight alpha and only pays ordinary quantization.
 
 AI-generated Blender code commonly trusts `Image.save()` to PNG for float
-RGBA scratch buffers (masks, ID mattes, AOVs). Pass --output to also render
-a staged still of two framed verification displays: left is the PNG-mangled
-reload, right is the EXR-clean reload.
+RGBA scratch buffers (masks, ID mattes, AOVs). ``--opaque-alpha`` authors
+every pixel at alpha 1.0 and still asserts the float→PNG error floor.
+That is the falsifier (``--same-axis`` in export-preset-axis). Pass --output
+to also render a staged still of two framed verification displays: left is
+the PNG-mangled reload, right is the EXR-clean reload.
 
     blender --background --python png_exr_alpha.py --
+    blender --background --python png_exr_alpha.py -- --opaque-alpha
     blender --background --python png_exr_alpha.py -- --output alpha.png
 """
 import bpy
@@ -86,11 +89,12 @@ def expected_byte_png_rgba(r, g, b, a):
     return (q8(r), q8(g), q8(b), q8(a))
 
 
-def fill_pattern(img):
+def fill_pattern(img, opaque_alpha=False):
     buf = [0.0] * (W * H * 4)
+    alphas = [1.0] * W if opaque_alpha else ALPHAS
     for y, rgb in enumerate(COLORS):
         r, g, b = rgb
-        for x, a in enumerate(ALPHAS):
+        for x, a in enumerate(alphas):
             i = (y * W + x) * 4
             buf[i : i + 4] = [r, g, b, a]
     img.pixels.foreach_set(buf)
@@ -169,7 +173,7 @@ def png_bit_depth(path):
     return None, None
 
 
-def check():
+def check(opaque_alpha=False):
     bpy.ops.wm.read_factory_settings(use_empty=True)
 
     # --- Closed-form worst case on this palette (independent of Blender) ---
@@ -198,7 +202,7 @@ def check():
     img_f = new_float_image("FloatSrc")
     if not img_f.is_float:
         return fail("float_buffer=True image reports is_float=False", 3)
-    orig = fill_pattern(img_f)
+    orig = fill_pattern(img_f, opaque_alpha=opaque_alpha)
     png_got, png_path = save_and_reload(img_f, "PNG", "png")
 
     bit, color = png_bit_depth(png_path)
@@ -651,9 +655,13 @@ def main():
         "--engine", default="eevee", choices=("eevee", "cycles"),
         help="render engine for --output (cycles for GPU-less hosts)",
     )
+    p.add_argument(
+        "--opaque-alpha", action="store_true",
+        help="falsifier: author alpha=1.0, still assert the float→PNG error floor",
+    )
     args = p.parse_args(argv)
 
-    code = check()
+    code = check(opaque_alpha=args.opaque_alpha)
     if code != 0:
         return code
     if args.output:
diff --git a/examples/shader-node-group/README.md b/examples/shader-node-group/README.md
index 32be36c..b26ec9a 100644
--- a/examples/shader-node-group/README.md
+++ b/examples/shader-node-group/README.md
@@ -18,12 +18,31 @@ colors.
 # Cheap correctness check (no render) — the CI check:
 blender --background --python shader_node_group.py --
 
+# Falsifier: identical instance Tints. Must exit non-zero.
+blender --background --python shader_node_group.py -- --same-tint
+
 # Also render a still (EEVEE on a GPU host; use --engine cycles on GPU-less hosts):
 blender --background --python shader_node_group.py -- --output spheres.png
 blender --background --python shader_node_group.py -- --output spheres.png --engine cycles
 ```
 
-It exits non-zero on failure (missing interface sockets, unshared group, or identical
-instance parameters). The `blender-smoke` workflow runs the check on Blender 5.2 LTS and 4.5 LTS.
+## Exit codes
+
+Per-script sequential checks. `9` is a valid check code; there is no rule
+against it. `10` is the shared framing helper.
+
+| Code | Meaning |
+| --- | --- |
+| 0 | Success |
+| 1 | Uncaught exception (FATAL wrapper) |
+| 2 | argparse / usage |
+| 3 | Interface sockets missing Tint / Roughness / Shader |
+| 4 | Group datablock `users` ≠ 2 |
+| 5 | Instance points at a different node tree |
+| 6 | Instance Tint values identical (`--same-tint` lands here) |
+| 7 | `--output` produced no file |
+| 10 | Gallery framing violation |
 
-The `--output` render path additionally measures framing against the Layer 1 band via `examples/gallery_framing.py` (exit 10 on violation) before writing the still.
+The `blender-smoke` workflow runs the check on Blender 5.2 LTS and 4.5 LTS
+(5.1 on the weekly cron, the `needs-5.1` PR label, or manual dispatch).
+Smoke does not pass `--output` or `--same-tint`.
diff --git a/examples/shader-node-group/shader_node_group.py b/examples/shader-node-group/shader_node_group.py
index 8374780..d4e1edd 100644
--- a/examples/shader-node-group/shader_node_group.py
+++ b/examples/shader-node-group/shader_node_group.py
@@ -8,10 +8,15 @@
 datablock (users == 2), and their instance-level Tint values differ — the
 whole point of grouping.
 
+``--same-tint`` copies SphereA's Tint onto both instances and still asserts
+the values differ. That is the falsifier (``--same-axis`` in
+export-preset-axis).
+
 By default it runs only the correctness check (no render) — the CI smoke
 check. Pass --output to also render a still:
 
     blender --background --python shader_node_group.py --                 # check only
+    blender --background --python shader_node_group.py -- --same-tint     # must fail
     blender --background --python shader_node_group.py -- --output s.png  # + render
 """
 import bpy, bmesh, sys, os, math, argparse
@@ -59,7 +64,7 @@ def material_from_group(name, tree, tint):
     return mat
 
 
-def build_scene():
+def build_scene(same_tint=False):
     bpy.ops.wm.read_factory_settings(use_empty=True)
     tree = build_group()
     objs = []
@@ -75,7 +80,8 @@ def build_scene():
         obj.location = (-1.35 + i * 2.7, 0.0, 1.0)
         for poly in me.polygons:
             poly.use_smooth = True
-        me.materials.append(material_from_group(f"Mat.{name}", tree, tint))
+        inst_tint = TINTS["SphereA"] if same_tint else tint
+        me.materials.append(material_from_group(f"Mat.{name}", tree, inst_tint))
         bpy.context.collection.objects.link(obj)
         objs.append(obj)
     return tree, objs
@@ -199,9 +205,12 @@ def main():
     p.add_argument("--output", default=None, help="optional: render a still PNG here")
     p.add_argument("--engine", default="eevee", choices=("eevee", "cycles"),
                    help="render engine for --output (cycles for GPU-less hosts)")
+    p.add_argument("--same-tint", action="store_true",
+                   help="falsifier: identical instance Tints, still assert they differ")
     args = p.parse_args(argv)
 
-    tree, objs = build_scene()
+    tree, objs = build_scene(same_tint=args.same_tint)
+
     code = check(tree, objs)
     if code:
         return code
diff --git a/examples/sky-texture-sun-elevation/README.md b/examples/sky-texture-sun-elevation/README.md
index d67069e..4690962 100644
--- a/examples/sky-texture-sun-elevation/README.md
+++ b/examples/sky-texture-sun-elevation/README.md
@@ -54,9 +54,31 @@ props"` rather than enforcing.
 # Zenith-luminance correctness check (tiny Cycles CPU EXR probes) — the CI check:
 blender --background --python sky_texture_sun_elevation.py --
 
+# Falsifier: Sky→Background unlinked. Must exit non-zero (world links).
+blender --background --python sky_texture_sun_elevation.py -- --unlink-sky
+
 # Also render the gallery diptych (Cycles):
 blender --background --python sky_texture_sun_elevation.py -- --output sky.png
 ```
 
-It exits non-zero on failure. The `blender-smoke` workflow runs the check on
-Blender 5.2 LTS and 4.5 LTS.
+## Exit codes
+
+Per-script sequential checks. `9` is a valid check code; there is no rule
+against it.
+
+| Code | Meaning |
+| --- | --- |
+| 0 | Success |
+| 1 | Uncaught exception (FATAL wrapper) |
+| 2 | argparse / usage |
+| 3 | `sky_type` is not the identifier for this Blender |
+| 4 | `sun_elevation` round-trip failed |
+| 5 | `dust_density` / `aerosol_density` / `NISHITA` / `MULTIPLE_SCATTERING` trap |
+| 6 | Sky → Background → World Output links broken (`--unlink-sky` lands here) |
+| 7 | High-elevation zenith luma below floor |
+| 8 | Zenith luma did not rise with elevation |
+| 9 | `--output` produced no file |
+
+The `blender-smoke` workflow runs the check on Blender 5.2 LTS and 4.5 LTS
+(5.1 on the weekly cron, the `needs-5.1` PR label, or manual dispatch).
+Smoke does not pass `--output` or `--unlink-sky`.
diff --git a/examples/sky-texture-sun-elevation/sky_texture_sun_elevation.py b/examples/sky-texture-sun-elevation/sky_texture_sun_elevation.py
index c870ef2..b1d02cd 100644
--- a/examples/sky-texture-sun-elevation/sky_texture_sun_elevation.py
+++ b/examples/sky-texture-sun-elevation/sky_texture_sun_elevation.py
@@ -12,10 +12,15 @@
 4. ``sun_elevation`` is load-bearing: raising it brightens zenith luminance
    — proven with two tiny Cycles EXR probes (straight-up camera) in one check.
 
+``--unlink-sky`` drops the Sky → Background Color link and still asserts
+the chain. That is the falsifier (``--same-axis`` in export-preset-axis).
+The sky_type / dust_density version traps are untouched.
+
 By default it runs the correctness check (tiny Cycles CPU renders, no gallery
 still). Pass --output to also render a still:
 
     blender --background --python sky_texture_sun_elevation.py --
+    blender --background --python sky_texture_sun_elevation.py -- --unlink-sky
     blender --background --python sky_texture_sun_elevation.py -- --output s.png
 """
 import bpy, bmesh, sys, os, math, argparse, tempfile, shutil
@@ -304,7 +309,12 @@ def check_links(world):
     return 0
 
 
-def check(sc, world, sky, bg):
+def check(sc, world, sky, bg, unlink_sky=False):
+    if unlink_sky:
+        nt = world.node_tree
+        for link in list(nt.links):
+            if link.from_node == sky and link.to_node.name == "Background":
+                nt.links.remove(link)
     code = check_links(world)
     if code:
         return code
@@ -502,11 +512,16 @@ def main():
         choices=("eevee", "cycles"),
         help="render engine for --output (cycles default: sky is a Cycles strength)",
     )
+    p.add_argument(
+        "--unlink-sky",
+        action="store_true",
+        help="falsifier: drop Sky→Background link, still assert the chain",
+    )
     args = p.parse_args(argv)
 
     print(f"binary version: {bpy.app.version} ({bpy.app.version_string})")
     sc, world, sky, bg = build_scene()
-    code = check(sc, world, sky, bg)
+    code = check(sc, world, sky, bg, unlink_sky=args.unlink_sky)
     if code:
         return code
 
diff --git a/examples/text-version-stamp/README.md b/examples/text-version-stamp/README.md
index 199a40b..509e374 100644
--- a/examples/text-version-stamp/README.md
+++ b/examples/text-version-stamp/README.md
@@ -28,15 +28,36 @@ on every LTS build; branch on the `bpy.app.version` tuple instead.
 # Cheap correctness check (no render) — the CI check:
 blender --background --python text_version_stamp.py --
 
+# Falsifier: body is not version_string. Must exit non-zero.
+blender --background --python text_version_stamp.py -- --wrong-body
+
 # Also render a still (EEVEE on a GPU host; use --engine cycles on GPU-less hosts):
 blender --background --python text_version_stamp.py -- --output stamp.png
 blender --background --python text_version_stamp.py -- --output stamp.png --engine cycles
 ```
 
-It exits non-zero on failure (wrong subclass, missing font, body/version mismatch,
-non-planar flat text, extrude/bevel closed form off, geometry not regenerating, or a
-`to_mesh_clear()` reference surviving). The `blender-smoke` workflow runs the check on
-Blender 5.2 LTS and 4.5 LTS. The render scales the stamp to a constant width, so the frame
-holds for any version-string length.
-
-The `--output` render path additionally measures framing against the Layer 1 band via `examples/gallery_framing.py` (exit 10 on violation) before writing the still.
+The render scales the stamp to a constant width, so the frame holds for any
+version-string length.
+
+## Exit codes
+
+Per-script sequential checks. `9` is a valid check code; there is no rule
+against it. `10` is the shared framing helper.
+
+| Code | Meaning |
+| --- | --- |
+| 0 | Success |
+| 1 | Uncaught exception (FATAL wrapper) |
+| 2 | argparse / usage |
+| 3 | Not a FONT `TextCurve` with the built-in Bfont |
+| 4 | `body` is not the live `version_string` (`--wrong-body` lands here) |
+| 5 | Flat text is not a filled planar mesh |
+| 6 | Extrude / bevel closed form failed |
+| 7 | Appending characters did not widen the text |
+| 8 | Mesh survived `to_mesh_clear()` |
+| 9 | `--output` produced no file |
+| 10 | Gallery framing violation |
+
+The `blender-smoke` workflow runs the check on Blender 5.2 LTS and 4.5 LTS
+(5.1 on the weekly cron, the `needs-5.1` PR label, or manual dispatch).
+Smoke does not pass `--output` or `--wrong-body`.
diff --git a/examples/text-version-stamp/text_version_stamp.py b/examples/text-version-stamp/text_version_stamp.py
index 28bf92c..25768e0 100644
--- a/examples/text-version-stamp/text_version_stamp.py
+++ b/examples/text-version-stamp/text_version_stamp.py
@@ -15,11 +15,16 @@
 `to_mesh_clear()` the returned Mesh reference is dead and any access raises
 ReferenceError.
 
+``--wrong-body`` assigns a string that is not ``version_string`` and still
+asserts the body is the live version. That is the falsifier (``--same-axis``
+in export-preset-axis).
+
 By default it runs only the correctness check (no render) — the CI smoke
 check. Pass --output to also render a still:
 
-    blender --background --python text_version_stamp.py --                 # check only
-    blender --background --python text_version_stamp.py -- --output v.png  # + render
+    blender --background --python text_version_stamp.py --                   # check only
+    blender --background --python text_version_stamp.py -- --wrong-body      # must fail
+    blender --background --python text_version_stamp.py -- --output v.png    # + render
 """
 import bpy, sys, os, math, argparse
 
@@ -33,10 +38,10 @@
 TOL = 1e-4
 
 
-def build_stamp():
+def build_stamp(wrong_body=False):
     bpy.ops.wm.read_factory_settings(use_empty=True)
     txt = bpy.data.curves.new("VersionStamp", type='FONT')
-    txt.body = bpy.app.version_string  # the self-documenting payload
+    txt.body = "not-a-version" if wrong_body else bpy.app.version_string
     txt.align_x = 'CENTER'
     txt.align_y = 'CENTER'
     obj = bpy.data.objects.new("VersionStamp", txt)
@@ -285,9 +290,12 @@ def main():
     p.add_argument("--output", default=None, help="optional: render a still PNG here")
     p.add_argument("--engine", default="eevee", choices=("eevee", "cycles"),
                    help="render engine for --output (cycles for GPU-less hosts)")
+    p.add_argument("--wrong-body", action="store_true",
+                   help="falsifier: body is not version_string, still assert it is")
     args = p.parse_args(argv)
 
-    obj = build_stamp()
+    obj = build_stamp(wrong_body=args.wrong_body)
+
     code = check(obj)
     if code:
         return code
diff --git a/examples/turntable/README.md b/examples/turntable/README.md
index d202771..3987b1a 100644
--- a/examples/turntable/README.md
+++ b/examples/turntable/README.md
@@ -16,6 +16,9 @@ channelbag comes from `action_ensure_channelbag_for_slot`; on 4.4/4.5 from
 # Cheap correctness check only (no render) — the CI smoke check:
 blender --background --python turntable.py --
 
+# Falsifier: no rotation keys. Must exit non-zero (keys drive playback).
+blender --background --python turntable.py -- --no-keys
+
 # Also render one still (EEVEE on a GPU host; use --engine cycles on GPU-less hosts):
 blender --background --python turntable.py -- --output turntable.png
 blender --background --python turntable.py -- --output turntable.png --engine cycles
@@ -23,6 +26,23 @@ blender --background --python turntable.py -- --output turntable.png --engine cy
 
 By default it runs only the **frame-independent correctness check**: it inserts the rotation
 keys, samples the object's Z rotation at frame 1 vs a later frame, and asserts they **differ**
-(the keys drive playback). It exits non-zero on failure — the same check the `blender-smoke`
-workflow runs on Blender 5.2 LTS and 4.5 LTS. `--output` additionally renders a still; the full
-animated loop is a showcase extra, not part of the CI check.
+(the keys drive playback). `--output` additionally renders a still; the full animated loop is
+a showcase extra, not part of the CI check.
+
+## Exit codes
+
+Per-script sequential checks. `9` is a valid check code; there is no rule
+against it.
+
+| Code | Meaning |
+| --- | --- |
+| 0 | Success |
+| 1 | Uncaught exception (FATAL wrapper) |
+| 2 | argparse / usage |
+| 3 | Rotation keys do not drive playback (`--no-keys` lands here) |
+| 4 | `--output` produced no file |
+| 5 | Wrong-era EEVEE engine id was accepted |
+
+The `blender-smoke` workflow runs the check on Blender 5.2 LTS and 4.5 LTS
+(5.1 on the weekly cron, the `needs-5.1` PR label, or manual dispatch).
+Smoke does not pass `--output` or `--no-keys`.
diff --git a/examples/turntable/turntable.py b/examples/turntable/turntable.py
index 65290ac..85924bb 100644
--- a/examples/turntable/turntable.py
+++ b/examples/turntable/turntable.py
@@ -10,7 +10,12 @@
 they DIFFER -- proving the keys drive playback. Exits non-zero on failure. This is the check
 the CI smoke gate runs on both builds.
 
+``--no-keys`` skips inserting the rotation keys and still asserts they drive playback.
+That is the falsifier (``--same-axis`` in export-preset-axis). The EEVEE-id
+era check is untouched.
+
     blender --background --python turntable.py --                 # correctness check only
+    blender --background --python turntable.py -- --no-keys       # must fail
     blender --background --python turntable.py -- --output t.png  # also render one still
     blender --background --python turntable.py -- --output t.png --engine cycles  # GPU-less
 """
@@ -29,7 +34,7 @@ def get_channelbag_for_slot(action, slot):
     strip = layer.strips[0] if layer.strips else layer.strips.new(type='KEYFRAME')
     return strip.channelbag(slot, ensure=True)
 
-def build():
+def build(no_keys=False):
     bpy.ops.wm.read_factory_settings(use_empty=True)
     bpy.ops.mesh.primitive_monkey_add(location=(0, 0, 1.0))
     obj = bpy.context.active_object
@@ -48,11 +53,12 @@ def build():
         slot = act.slots.new(id_type='OBJECT', name=obj.name); obj.animation_data.action_slot = slot
     cbag = get_channelbag_for_slot(act, slot)
     fc = cbag.fcurves.new("rotation_euler", index=2)
-    fc.keyframe_points.insert(1, 0.0)
-    fc.keyframe_points.insert(FRAMES, math.radians(360))
-    for kp in fc.keyframe_points:
-        kp.interpolation = 'LINEAR'
-    fc.update()
+    if not no_keys:
+        fc.keyframe_points.insert(1, 0.0)
+        fc.keyframe_points.insert(FRAMES, math.radians(360))
+        for kp in fc.keyframe_points:
+            kp.interpolation = 'LINEAR'
+        fc.update()
     return obj
 
 def correctness(obj):
@@ -122,6 +128,8 @@ def main():
     p = argparse.ArgumentParser()
     p.add_argument("--output", default=None, help="optional: render one still to this PNG")
     p.add_argument("--engine", choices=["auto", "cycles"], default="auto")
+    p.add_argument("--no-keys", action="store_true",
+                   help="falsifier: skip rotation keys, still assert they drive playback")
     args = p.parse_args(argv)
 
     # the EEVEE-id mapping is asserted regardless of whether we render: the
@@ -135,7 +143,7 @@ def main():
         pass  # correctly rejected
     bpy.context.scene.render.engine = eid  # raises TypeError if the helper's id is invalid
 
-    obj = build()
+    obj = build(no_keys=args.no_keys)
     if not correctness(obj):
         print("ERROR: rotation keys do not drive playback", file=sys.stderr); return 3
 
diff --git a/examples/vse-cut-list/README.md b/examples/vse-cut-list/README.md
index 813cf72..9da8c39 100644
--- a/examples/vse-cut-list/README.md
+++ b/examples/vse-cut-list/README.md
@@ -112,6 +112,10 @@ explicitly.
 # Cheap correctness check (no render) — the CI check:
 blender --background --python vse_cut_list.py --
 
+# Falsifier: GC T2 -> T1. Must exit non-zero (wiring). `--check-pixels` is a
+# second witness, not this falsifier.
+blender --background --python vse_cut_list.py -- --swap-inputs
+
 # Compositing witness on a tiny render (Cycles CPU, CI-safe):
 blender --background --python vse_cut_list.py -- --check-pixels --engine cycles
 
@@ -119,8 +123,27 @@ blender --background --python vse_cut_list.py -- --check-pixels --engine cycles
 blender --background --python vse_cut_list.py -- --output vse.png
 ```
 
-It exits non-zero on failure and prints every measured value and tolerance on
-success, so CI logs carry the numbers. The `blender-smoke` workflow runs the
-check and the pixel witness on Blender 5.2 LTS and 4.5 LTS.
-
-The `--output` render path additionally measures framing against the Layer 1 band via `examples/gallery_framing.py` (exit 10 on violation) before writing the still.
+## Exit codes
+
+Per-script sequential checks. `9` is a valid check code; there is no rule
+against it. `10` is also the shared framing helper.
+
+| Code | Meaning |
+| --- | --- |
+| 0 | Success |
+| 1 | Uncaught exception (FATAL wrapper) |
+| 2 | argparse / usage |
+| 3 | `.sequences` accessor contract for this Blender |
+| 4 | Wrong-era `new_effect` end kwarg or TRANSFORM type did not TypeError |
+| 5 | Strip span or channel off closed form |
+| 6 | `frame_final_*` deprecation bridge for this Blender |
+| 7 | GC wiring or strip `.type` enum (`--swap-inputs` lands here) |
+| 8 | Scene strip span or Stage source |
+| 9 | Mosaic transform, compositing defaults, text body, or strip color |
+| 10 | Save/reload round-trip re-assert failed; also gallery framing violation |
+| 11 | `--output` produced no file |
+| 12 | `--check-pixels` compositing contract |
+
+The `blender-smoke` workflow runs the check and the pixel witness on Blender
+5.2 LTS and 4.5 LTS (5.1 on the weekly cron, the `needs-5.1` PR label, or
+manual dispatch). Smoke does not pass `--output` or `--swap-inputs`.
diff --git a/examples/vse-cut-list/vse_cut_list.py b/examples/vse-cut-list/vse_cut_list.py
index a1bf991..5eeb8a7 100644
--- a/examples/vse-cut-list/vse_cut_list.py
+++ b/examples/vse-cut-list/vse_cut_list.py
@@ -31,6 +31,10 @@
   The timeline below therefore feeds the cross a dedicated source pair
   (T1/T2) that owns no mosaic cell, on channels directly under GC.
 
+``--swap-inputs`` wires GC as T2 -> T1 and still asserts T1 -> T2. That is
+the falsifier (``--same-axis`` in export-preset-axis). ``--check-pixels``
+remains a second witness, not a falsifier.
+
 The check builds a deterministic cut list, asserts every span against its
 closed form on each version's canonical accessors, then proves the spans,
 wiring, colors, and transforms survive a save/reload round-trip. Pass
@@ -40,6 +44,7 @@
 tiny render (cell colors and input consumption), the way CI does:
 
     blender --background --python vse_cut_list.py --
+    blender --background --python vse_cut_list.py -- --swap-inputs
     blender --background --python vse_cut_list.py -- --check-pixels
     blender --background --python vse_cut_list.py -- --output vse.png
 """
@@ -314,10 +319,15 @@ def check_roundtrip():
     return check(bpy.context.scene)
 
 
-def run_checks():
+def run_checks(swap_inputs=False):
     bpy.ops.wm.read_factory_settings(use_empty=True)
     sc = bpy.context.scene
     build_cut_list(sc)
+    if swap_inputs:
+        coll = strips_coll(sc.sequence_editor)
+        gc = coll.get("GC")
+        gc.input_1 = coll.get("T2")
+        gc.input_2 = coll.get("T1")
     code = check(sc)
     if code != 0:
         return code
@@ -690,9 +700,13 @@ def main():
         "--check-pixels", action="store_true",
         help="also assert the compositing contract on a tiny render",
     )
+    p.add_argument(
+        "--swap-inputs", action="store_true",
+        help="falsifier: GC T2 -> T1, still assert T1 -> T2",
+    )
     args = p.parse_args(argv)
 
-    code = run_checks()
+    code = run_checks(swap_inputs=args.swap_inputs)
     if code != 0:
         return code
     if args.check_pixels:
diff --git a/examples/vse-gamma-cross/README.md b/examples/vse-gamma-cross/README.md
index de217b9..e75f659 100644
--- a/examples/vse-gamma-cross/README.md
+++ b/examples/vse-gamma-cross/README.md
@@ -52,11 +52,31 @@ identical, so the still visibly breaks with the contract.
 # Correctness check (tiny per-frame sample renders) — the CI check:
 blender --background --python vse_gamma_cross.py --
 
+# Falsifier: GC T2 -> T1. Must exit non-zero (inputs).
+blender --background --python vse_gamma_cross.py -- --swap-inputs
+
 # Also render the calibration lightbox still (EEVEE on a GPU host; cycles on GPU-less):
 blender --background --python vse_gamma_cross.py -- --output bench.png
 blender --background --python vse_gamma_cross.py -- --output bench.png --engine cycles
 ```
 
-It exits non-zero on failure (span drift, wrong inputs, t-convention drift,
-a sample off the closed form, or a missing gamma dip). The `blender-smoke`
-workflow runs the check on Blender 5.2 LTS and 4.5 LTS.
+## Exit codes
+
+Per-script sequential checks. `9` is a valid check code; there is no rule
+against it.
+
+| Code | Meaning |
+| --- | --- |
+| 0 | Success |
+| 1 | Uncaught exception (FATAL wrapper) |
+| 2 | argparse / usage |
+| 3 | GC span off closed form |
+| 4 | GC inputs are not T1 → T2 (`--swap-inputs` lands here) |
+| 5 | Sample `t` convention drifted |
+| 6 | Cross sample off the gamma-0.5 closed form |
+| 7 | Mid-cross lerp deviation missing (naive mix) |
+| 8 | `--output` produced no file |
+
+The `blender-smoke` workflow runs the check on Blender 5.2 LTS and 4.5 LTS
+(5.1 on the weekly cron, the `needs-5.1` PR label, or manual dispatch).
+Smoke does not pass `--output` or `--swap-inputs`.
diff --git a/examples/vse-gamma-cross/vse_gamma_cross.py b/examples/vse-gamma-cross/vse_gamma_cross.py
index 3330b8f..1615e49 100644
--- a/examples/vse-gamma-cross/vse_gamma_cross.py
+++ b/examples/vse-gamma-cross/vse_gamma_cross.py
@@ -21,11 +21,15 @@
 The blend math is identical on Blender 4.5 LTS and 5.1 (every sample matches
 to the quantization step).
 
+``--swap-inputs`` wires GC as T2 -> T1 and still asserts T1 -> T2. That is
+the falsifier (``--same-axis`` in export-preset-axis).
+
 By default it runs only the correctness check (no gallery render) — the CI
 smoke check. Pass --output to also render a still:
 
-    blender --background --python vse_gamma_cross.py --                 # check only
-    blender --background --python vse_gamma_cross.py -- --output g.png  # + render
+    blender --background --python vse_gamma_cross.py --                   # check only
+    blender --background --python vse_gamma_cross.py -- --swap-inputs     # must fail
+    blender --background --python vse_gamma_cross.py -- --output g.png    # + render
 """
 import bpy, sys, os, math, argparse, tempfile, shutil
 
@@ -69,7 +73,7 @@ def strip_span(s):
     return s.frame_final_start, s.frame_final_end, s.frame_final_duration
 
 
-def build_cross(sc):
+def build_cross(sc, swap_inputs=False):
     """The two-strip cross: T1/T2 consumed by the GAMMA_CROSS above them
     (effect strips consume inputs only from below — vse-cut-list's wiring)."""
     sc.frame_start = SPAN[0]
@@ -80,7 +84,8 @@ def build_cross(sc):
     t1.color = A_RGB
     t2 = new_effect(coll, "T2", "COLOR", 2, SPAN)
     t2.color = B_RGB
-    gc = new_effect(coll, "GC", "GAMMA_CROSS", 3, SPAN, input1=t1, input2=t2)
+    src1, src2 = (t2, t1) if swap_inputs else (t1, t2)
+    gc = new_effect(coll, "GC", "GAMMA_CROSS", 3, SPAN, input1=src1, input2=src2)
     return gc
 
 
@@ -411,11 +416,13 @@ def main():
     p.add_argument("--output", default=None, help="optional: render a still PNG here")
     p.add_argument("--engine", default="eevee", choices=("eevee", "cycles"),
                    help="render engine for --output (cycles for GPU-less hosts)")
+    p.add_argument("--swap-inputs", action="store_true",
+                   help="falsifier: GC T2 -> T1, still assert T1 -> T2")
     args = p.parse_args(argv)
 
     bpy.ops.wm.read_factory_settings(use_empty=True)
     sc = bpy.context.scene
-    gc = build_cross(sc)
+    gc = build_cross(sc, swap_inputs=args.swap_inputs)
     code = check(sc, gc)
     if code:
         return code

From 8d1b1c5eb6b4b34424f5bc59338d77befb7729a9 Mon Sep 17 00:00:00 2001
From: TMHSDigital <154358121+TMHSDigital@users.noreply.github.com>
Date: Sun, 13 Sep 2026 10:30:20 -0400
Subject: [PATCH 2/2] docs: backfill README exit tables on the remaining
 thirteen examples

Inspection-only documentation so every shipped example lists its file-local
nonzero codes. No flags, no behavior, no code-value changes.

Signed-off-by: TMHSDigital <154358121+TMHSDigital@users.noreply.github.com>
Co-authored-by: Cursor <cursoragent@cursor.com>
---
 examples/coincident-vert-weld/README.md       | 17 +++++++++
 .../cross-version-property-delete/README.md   | 22 ++++++++++++
 examples/exit-pre-sidecar/README.md           | 28 ++++++++++-----
 examples/export-preset-axis/README.md         | 27 +++++++++++---
 examples/gn-bundle-roundtrip/README.md        | 20 +++++++++++
 examples/gn-zone-iterate/README.md            | 22 ++++++++++++
 examples/lightmap-uv-channel/README.md        | 28 ++++++++++++---
 examples/modular-kit-snap/README.md           | 27 +++++++++++---
 examples/ngon-triangulate/README.md           | 17 +++++++++
 examples/socket-attach-points/README.md       | 30 ++++++++++++++--
 examples/unapplied-scale-gltf/README.md       | 17 +++++++++
 examples/usd-export-evaluation-mode/README.md | 21 +++++++++++
 examples/vertex-color-ao/README.md            | 35 +++++++++++++++----
 13 files changed, 281 insertions(+), 30 deletions(-)

diff --git a/examples/coincident-vert-weld/README.md b/examples/coincident-vert-weld/README.md
index 7a90cd7..2b9bfff 100644
--- a/examples/coincident-vert-weld/README.md
+++ b/examples/coincident-vert-weld/README.md
@@ -33,3 +33,20 @@ blender --background --python coincident_vert_weld.py --
 blender --background --python coincident_vert_weld.py -- --no-duplicate
 blender --background --python coincident_vert_weld.py -- --weld
 ```
+
+## Exit codes
+
+Per-script sequential checks. `9` is a valid check code; there is no rule
+against it.
+
+| Code | Meaning |
+| --- | --- |
+| 0 | Success |
+| 1 | Uncaught exception (FATAL wrapper) |
+| 2 | argparse / usage; also exporter RNA missing expected glTF kwargs |
+| 3 | Pathology missing: coincident shells (`--no-duplicate` lands here) |
+| 4 | glTF export handling failed (`--weld` lands here) |
+
+The `blender-smoke` workflow runs the check on Blender 5.2 LTS and 4.5 LTS
+(5.1 on the weekly cron, the `needs-5.1` PR label, or manual dispatch).
+Smoke does not pass `--no-duplicate` or `--weld`.
diff --git a/examples/cross-version-property-delete/README.md b/examples/cross-version-property-delete/README.md
index 93d0ac4..3dda544 100644
--- a/examples/cross-version-property-delete/README.md
+++ b/examples/cross-version-property-delete/README.md
@@ -36,3 +36,25 @@ the Clear plate tagged and exit 7.
 
 The `--output` render path measures framing against the Layer 1 band via
 `examples/gallery_framing.py` (exit 10 on violation) before writing the still.
+
+## Exit codes
+
+Per-script sequential checks. `9` is a valid check code; there is no rule
+against it. `10` is the shared framing helper.
+
+| Code | Meaning |
+| --- | --- |
+| 0 | Success |
+| 1 | Uncaught exception (FATAL wrapper) |
+| 2 | argparse / usage; also an active object existed after the data-API build |
+| 3 | Custom ID property did not land |
+| 4 | `property_unset` on a custom ID key did not TypeError, or it deleted the key |
+| 5 | `del` did not report removal |
+| 6 | Keep plate lost the ID property |
+| 7 | Clear plate still has the ID property (`--skip-delete` / `--unset-instead` land here) |
+| 10 | Gallery framing violation |
+| 12 | `--output` produced no file |
+
+The `blender-smoke` workflow runs the check on Blender 5.2 LTS and 4.5 LTS
+(5.1 on the weekly cron, the `needs-5.1` PR label, or manual dispatch).
+Smoke does not pass `--output`, `--skip-delete`, or `--unset-instead`.
diff --git a/examples/exit-pre-sidecar/README.md b/examples/exit-pre-sidecar/README.md
index 2286044..ea82507 100644
--- a/examples/exit-pre-sidecar/README.md
+++ b/examples/exit-pre-sidecar/README.md
@@ -12,16 +12,10 @@ accessing the handler list.
 
 No gallery still. There is no geometry.
 
-**What failure each check would catch:**
-
-- exit 77 — Blender &lt; 5.1 and not `--force-run`
-- exit 2 — `--force-run` on 4.5 (`exit_pre` missing)
-- harness FAIL missing sidecar — `--silent-handler` / `--no-handler`
-- harness FAIL wrong contents — `--wrong-text` (`nope`), `--write-in-main`
-  (`from-main`), `--atexit-instead` (`atexit-ok`)
-
 The harness checks **contents** (`sidecar_contains=exit_pre-ok`), not
-existence only. A file written from `main` or `atexit` is red.
+existence only. A file written from `main` or `atexit` is red. Several
+falsifiers exit 0 from the script so the **harness** can fail after Blender
+dies.
 
 ## Run
 
@@ -33,3 +27,19 @@ python tests/smoke/run_example.py --name exit-pre-sidecar \
   --series 5.2 --min-version 5.1 \
   --expect-sidecar /tmp/exit-pre.sidecar --sidecar-contains exit_pre-ok
 ```
+
+## Exit codes
+
+Per-script sequential checks. `9` is a valid check code; there is no rule
+against it. `77` is the smoke skip protocol, not a product check.
+
+| Code | Meaning |
+| --- | --- |
+| 0 | Success (including `--silent-handler` / `--no-handler` / `--wrong-text` / `--write-in-main` / `--atexit-instead`, which the harness then fails) |
+| 1 | Uncaught exception (FATAL wrapper); also `$BDT_SMOKE_SIDECAR` unset |
+| 2 | argparse / usage; also `--force-run` on Blender &lt; 5.1 (`exit_pre` missing or unexpectedly present) |
+| 77 | `SMOKE_SKIP:` `exit_pre` requires Blender 5.1+ |
+
+The `blender-smoke` workflow runs the check on Blender 5.2 LTS (5.1 on the
+weekly cron, the `needs-5.1` PR label, or manual dispatch) and skips on 4.5
+LTS. Smoke does not pass the falsifier flags.
diff --git a/examples/export-preset-axis/README.md b/examples/export-preset-axis/README.md
index 5ead816..dc84ad7 100644
--- a/examples/export-preset-axis/README.md
+++ b/examples/export-preset-axis/README.md
@@ -43,7 +43,26 @@ blender --background --python export_preset_axis.py -- --output beacon.png
 blender --background --python export_preset_axis.py -- --output beacon.png --engine cycles
 ```
 
-It exits non-zero on failure (RNA drift, source not Z-dominant, Unity disk
-not converted, Godot disk not Z-up, Unity not standing, Godot not lying,
-orientations equal). The `blender-smoke` workflow runs the check on Blender
-5.2 LTS and 4.5 LTS (5.1 on the weekly cron).
+## Exit codes
+
+Per-script sequential checks. `9` is a valid check code; there is no rule
+against it. `10` is the shared framing helper.
+
+| Code | Meaning |
+| --- | --- |
+| 0 | Success |
+| 1 | Uncaught exception (FATAL wrapper) |
+| 2 | argparse / usage; also exporter RNA missing expected glTF kwargs |
+| 3 | Source mast is not Z-dominant, or tip drifted |
+| 4 | glTF reimport produced no mesh |
+| 5 | Unity disk POSITION is not `(x, z, -y)`, or Unity node has rotation |
+| 6 | Godot disk POSITION is not raw Z-up; also `--output` produced no file |
+| 7 | Unity reimport is not standing |
+| 8 | Godot reimport is not lying along Y, or reimported tip mismatch |
+| 9 | Reimported orientations did not differ (`--same-axis` lands here) |
+| 10 | Gallery framing violation |
+| 11 | `--same-axis` did not collapse the axis difference |
+
+The `blender-smoke` workflow runs the check on Blender 5.2 LTS and 4.5 LTS
+(5.1 on the weekly cron, the `needs-5.1` PR label, or manual dispatch).
+Smoke does not pass `--output` or `--same-axis`.
diff --git a/examples/gn-bundle-roundtrip/README.md b/examples/gn-bundle-roundtrip/README.md
index 6964e78..b01f3d0 100644
--- a/examples/gn-bundle-roundtrip/README.md
+++ b/examples/gn-bundle-roundtrip/README.md
@@ -43,3 +43,23 @@ not read at thumbnail.
 blender --background --python gn_bundle_roundtrip.py --
 blender --background --python gn_bundle_roundtrip.py -- --force-run
 ```
+
+## Exit codes
+
+Per-script sequential checks. `9` is a valid check code; there is no rule
+against it. `77` is the smoke skip protocol, not a product check.
+
+| Code | Meaning |
+| --- | --- |
+| 0 | Success |
+| 1 | Uncaught exception (FATAL wrapper) |
+| 2 | argparse / usage; carrier mesh rewritten; `--legacy-rna` on 5.x |
+| 3 | Evaluated vert/face count off closed form (`--mismatch`) |
+| 4 | Unpacked Scale/Offset x-extent off (`--bypass`) |
+| 5 | `bundle_mark` missing or off closed form |
+| 77 | `SMOKE_SKIP:` Bundles require Blender 5.0+ |
+
+The `blender-smoke` workflow runs the check on Blender 5.2 LTS (5.1 on the
+weekly cron, the `needs-5.1` PR label, or manual dispatch) and skips on 4.5
+LTS. Smoke does not pass `--bypass`, `--legacy-rna`, `--mismatch`, or
+`--force-run`.
diff --git a/examples/gn-zone-iterate/README.md b/examples/gn-zone-iterate/README.md
index 14e329d..81744ff 100644
--- a/examples/gn-zone-iterate/README.md
+++ b/examples/gn-zone-iterate/README.md
@@ -40,3 +40,25 @@ blender --background --python gn_zone_iterate.py -- --output zones.png
 
 The `--output` render path measures framing via `examples/gallery_framing.py`
 (exit 10 on violation).
+
+## Exit codes
+
+Per-script sequential checks. `9` is a valid check code; there is no rule
+against it. `10` is the shared framing helper.
+
+| Code | Meaning |
+| --- | --- |
+| 0 | Success |
+| 1 | Uncaught exception (FATAL wrapper) |
+| 2 | argparse / usage; also carrier mesh was rewritten |
+| 3 | Repeat evaluated vert/face count off closed form |
+| 4 | Repeat X-centers off closed form |
+| 5 | For Each evaluated vert/face count off closed form |
+| 6 | For Each Z-centers off closed form |
+| 10 | Gallery framing violation |
+| 12 | `--output` produced no file |
+
+The `blender-smoke` workflow runs the check on Blender 5.2 LTS and 4.5 LTS
+(5.1 on the weekly cron, the `needs-5.1` PR label, or manual dispatch).
+Smoke does not pass `--output`, `--no-offset`, `--unpair-foreach`, or
+`--unpair-repeat`.
diff --git a/examples/lightmap-uv-channel/README.md b/examples/lightmap-uv-channel/README.md
index c543e3e..c68317e 100644
--- a/examples/lightmap-uv-channel/README.md
+++ b/examples/lightmap-uv-channel/README.md
@@ -87,7 +87,27 @@ blender --background --python lightmap_uv_channel.py -- --output atlas.png
 blender --background --python lightmap_uv_channel.py -- --falsify overlap.png
 ```
 
-Exits non-zero on failure. The `blender-smoke` workflow runs the check on
-Blender 5.2 LTS and 4.5 LTS. The `--output` render path additionally measures
-framing against the Layer 1 band via `examples/gallery_framing.py` (exit 10
-on violation) before writing the still.
+## Exit codes
+
+Per-script sequential checks. `9` is a valid check code; there is no rule
+against it. `10` is the shared framing helper. `11` is the shared asset-quality
+helper.
+
+| Code | Meaning |
+| --- | --- |
+| 0 | Success |
+| 1 | Uncaught exception (FATAL wrapper) |
+| 2 | argparse / usage |
+| 3 | UV layer names ≠ UV0 / UV1 |
+| 4 | UVMap / UV1 render/clone flags wrong after re-assert |
+| 5 | Channel 0 (UV0) touched by the UV1 unwrap |
+| 6 | UV1 loops outside `[0,1]` |
+| 7 | SAT overlap self-test failed, or UV1 triangle pairs overlap |
+| 8 | Min island distance below margin |
+| 9 | Part is not watertight |
+| 10 | Gallery framing violation; also `--output` produced no file |
+| 11 | Gallery asset-quality violation |
+
+The `blender-smoke` workflow runs the check on Blender 5.2 LTS and 4.5 LTS
+(5.1 on the weekly cron, the `needs-5.1` PR label, or manual dispatch).
+Smoke does not pass `--output` or `--falsify`.
diff --git a/examples/modular-kit-snap/README.md b/examples/modular-kit-snap/README.md
index 7e1cc77..985a3a5 100644
--- a/examples/modular-kit-snap/README.md
+++ b/examples/modular-kit-snap/README.md
@@ -83,7 +83,26 @@ blender --background --python modular_kit_snap.py -- --output corridor.png
 blender --background --python modular_kit_snap.py -- --falsify seams.png
 ```
 
-Exits non-zero on failure. The `blender-smoke` workflow runs the check on
-Blender 5.2 LTS and 4.5 LTS. The `--output` render path additionally measures
-framing against the Layer 1 band via `examples/gallery_framing.py` (reported
-under the documented deviation above) before writing the still.
+## Exit codes
+
+Per-script sequential checks. `9` is a valid check code; there is no rule
+against it. `10` is the shared framing helper. `11` is the shared asset-quality
+helper.
+
+| Code | Meaning |
+| --- | --- |
+| 0 | Success |
+| 1 | Uncaught exception (FATAL wrapper) |
+| 2 | argparse / usage |
+| 3 | Boundary vert count or end-plane membership |
+| 4 | End rings do not partition evenly, or opposing loops differ |
+| 5 | Tiled instances do not share boundary positions |
+| 6 | Shell or whole-asset bbox off the declared tile |
+| 7 | Boundary edge count, non-manifold edges, or rim off the end planes |
+| 8 | Detail part not watertight |
+| 9 | Detail part reaches a tile boundary; also `--output` produced no file |
+| 11 | Kit part count, unapplied scale, namespace, or origin; also gallery asset-quality violation |
+
+The `blender-smoke` workflow runs the check on Blender 5.2 LTS and 4.5 LTS
+(5.1 on the weekly cron, the `needs-5.1` PR label, or manual dispatch).
+Smoke does not pass `--output` or `--falsify`.
diff --git a/examples/ngon-triangulate/README.md b/examples/ngon-triangulate/README.md
index 50acdb2..320e8bf 100644
--- a/examples/ngon-triangulate/README.md
+++ b/examples/ngon-triangulate/README.md
@@ -29,3 +29,20 @@ blender --background --python ngon_triangulate.py --
 blender --background --python ngon_triangulate.py -- --no-dissolve
 blender --background --python ngon_triangulate.py -- --skip-triangulate
 ```
+
+## Exit codes
+
+Per-script sequential checks. `9` is a valid check code; there is no rule
+against it.
+
+| Code | Meaning |
+| --- | --- |
+| 0 | Success |
+| 1 | Uncaught exception (FATAL wrapper) |
+| 2 | argparse / usage |
+| 3 | Pathology missing: n-gon count, loops, or face count (`--no-dissolve` lands here) |
+| 4 | `calc_tangents` / triangulate handling (`--skip-triangulate` lands here) |
+
+The `blender-smoke` workflow runs the check on Blender 5.2 LTS and 4.5 LTS
+(5.1 on the weekly cron, the `needs-5.1` PR label, or manual dispatch).
+Smoke does not pass `--no-dissolve` or `--skip-triangulate`.
diff --git a/examples/socket-attach-points/README.md b/examples/socket-attach-points/README.md
index 2650862..64b2982 100644
--- a/examples/socket-attach-points/README.md
+++ b/examples/socket-attach-points/README.md
@@ -123,11 +123,35 @@ blender --background --python socket_attach_points.py -- --falsify adrift.png
 blender --background --python socket_attach_points.py -- --probe
 ```
 
-Exits non-zero on failure. The `blender-smoke` workflow runs the check on
-Blender 5.2 LTS and 4.5 LTS. The `--output` render path additionally gates framing
-via `examples/gallery_framing.py` (fill **0.881x**, margins
+The `--output` render path additionally gates framing via
+`examples/gallery_framing.py` (fill **0.881x**, margins
 **0.066/0.053/0.122/0.106**, no edge touched) and the asset floors via
 `examples/gallery_asset_quality.py` (32 materials, `edge90` **0.027**, no
 default names). The `--falsify` render is a diagnostic, not a gallery hero, so
 it takes a documented framing deviation — its whole point is that the modules
 leave the frame.
+
+## Exit codes
+
+Per-script sequential checks. `9` is a valid check code; there is no rule
+against it. `10` is the shared framing helper. `11` is the shared asset-quality
+helper.
+
+| Code | Meaning |
+| --- | --- |
+| 0 | Success |
+| 1 | Uncaught exception (FATAL wrapper) |
+| 2 | argparse / usage |
+| 3 | Socket world matrix, orthonormal basis, or determinant |
+| 4 | Socket pad normal, origin, or up-axis rule |
+| 5 | Module seating / mount axis / leftover local transform |
+| 6 | Population, namespace, default datablock name, SKT_ prefix, or skid plane |
+| 7 | Re-pose: socket or module lost the root |
+| 8 | Parent-inverse clear, child scale pushdown, or post-apply module drift |
+| 9 | `--output` produced no file |
+| 10 | Gallery framing violation |
+| 11 | Gallery asset-quality violation |
+
+The `blender-smoke` workflow runs the check on Blender 5.2 LTS and 4.5 LTS
+(5.1 on the weekly cron, the `needs-5.1` PR label, or manual dispatch).
+Smoke does not pass `--output`, `--falsify`, or `--probe`.
diff --git a/examples/unapplied-scale-gltf/README.md b/examples/unapplied-scale-gltf/README.md
index 2d5c988..879b724 100644
--- a/examples/unapplied-scale-gltf/README.md
+++ b/examples/unapplied-scale-gltf/README.md
@@ -31,3 +31,20 @@ blender --background --python unapplied_scale_gltf.py --
 blender --background --python unapplied_scale_gltf.py -- --identity
 blender --background --python unapplied_scale_gltf.py -- --bake
 ```
+
+## Exit codes
+
+Per-script sequential checks. `9` is a valid check code; there is no rule
+against it.
+
+| Code | Meaning |
+| --- | --- |
+| 0 | Success |
+| 1 | Uncaught exception (FATAL wrapper) |
+| 2 | argparse / usage; also exporter RNA missing expected glTF kwargs |
+| 3 | Pathology missing: unapplied non-uniform scale (`--identity` lands here) |
+| 4 | Export handling failed (`--bake` lands here) |
+
+The `blender-smoke` workflow runs the check on Blender 5.2 LTS and 4.5 LTS
+(5.1 on the weekly cron, the `needs-5.1` PR label, or manual dispatch).
+Smoke does not pass `--identity` or `--bake`.
diff --git a/examples/usd-export-evaluation-mode/README.md b/examples/usd-export-evaluation-mode/README.md
index bb2ef91..8cab633 100644
--- a/examples/usd-export-evaluation-mode/README.md
+++ b/examples/usd-export-evaluation-mode/README.md
@@ -41,3 +41,24 @@ true in `--background`, `evaluation_mode` is `{RENDER, VIEWPORT}`. The
 blender --background --python usd_export_evaluation_mode.py --
 blender --background --python usd_export_evaluation_mode.py -- --output u.png
 ```
+
+## Exit codes
+
+Per-script sequential checks. `9` is a valid check code; there is no rule
+against it. `10` is the shared framing helper.
+
+| Code | Meaning |
+| --- | --- |
+| 0 | Success |
+| 1 | Uncaught exception (FATAL wrapper) |
+| 2 | argparse / usage; also base cube verts ≠ 8 |
+| 3 | VIEWPORT TESSELLATE point/face count off closed form |
+| 4 | RENDER TESSELLATE point/face count or scheme off closed form |
+| 5 | BEST_MATCH cage point count or scheme off |
+| 6 | RENDER and VIEWPORT USDA point counts are identical |
+| 10 | Gallery framing violation |
+| 12 | `--output` produced no file |
+
+The `blender-smoke` workflow runs the check on Blender 5.2 LTS and 4.5 LTS
+(5.1 on the weekly cron, the `needs-5.1` PR label, or manual dispatch).
+Smoke does not pass `--output`, `--evaluation-mode`, or `--subdivision`.
diff --git a/examples/vertex-color-ao/README.md b/examples/vertex-color-ao/README.md
index 051c3c6..5e42d21 100644
--- a/examples/vertex-color-ao/README.md
+++ b/examples/vertex-color-ao/README.md
@@ -115,10 +115,33 @@ blender --background --python vertex_color_ao.py -- --output well.png
 blender --background --python vertex_color_ao.py -- --falsify inverted.png
 ```
 
-Exits non-zero on failure. The `blender-smoke` workflow runs the check on
-Blender 5.2 LTS and 4.5 LTS (the calibration rig gets 4096 samples over six
-points, the asset a cheap 64, so the whole check is ~1 s). The `--output`
-render path additionally gates framing via `examples/gallery_framing.py`
-(fill **0.839y**, margins **0.241/0.238/0.072/0.089**, no edge touched) and the
-asset floors via `examples/gallery_asset_quality.py` (11 materials, `edge90`
+The `--output` render path additionally gates framing via
+`examples/gallery_framing.py` (fill **0.839y**, margins
+**0.241/0.238/0.072/0.089**, no edge touched) and the asset floors via
+`examples/gallery_asset_quality.py` (11 materials, `edge90`
 **0.152**, no default names).
+
+## Exit codes
+
+Per-script sequential checks. `9` is a valid check code; there is no rule
+against it. `10` is the shared framing helper. `11` is the shared asset-quality
+helper.
+
+| Code | Meaning |
+| --- | --- |
+| 0 | Success |
+| 1 | Uncaught exception (FATAL wrapper) |
+| 2 | argparse / usage |
+| 3 | Calibration AO off closed form |
+| 4 | Unoccluded plate is not 1.0, or AO is not strictly increasing with distance |
+| 5 | Bake empty, out of range, or spread too small |
+| 6 | FLOAT_COLOR / BYTE_COLOR round-trip contract |
+| 7 | Colour attributes missing, retyped, or drifted under the depsgraph |
+| 8 | Asset part count, unapplied scale, namespace, render attribute, or ground plane |
+| 9 | `--output` produced no file |
+| 10 | Gallery framing violation |
+| 11 | Gallery asset-quality violation |
+
+The `blender-smoke` workflow runs the check on Blender 5.2 LTS and 4.5 LTS
+(5.1 on the weekly cron, the `needs-5.1` PR label, or manual dispatch).
+Smoke does not pass `--output` or `--falsify`.