docs(formulas): drop the M9.1 / M9.2 phase language from the docs page and the pending changesets (#17851)

The M9.1 / M9.2 expression phases — including the promise that `ast`
becomes required in build output — were asserted across the tree and
defined in no ADR. Decision batch #123 item 1 (director seat,
2026-09-12) ruled option **B**, maintainer verbatim 「同意」: the phase
assertions are removed, and `ast` stays an accepted optional persisted
form with no promise of becoming required. This PR is the **docs half**
of that ruling — the published docs page and the two still-unconsumed
changesets now state the contract in the present tense: `source` is the
canonical persisted form, `ast` is an optional opaque structured value.
Per the ruling's item 4 (「Files under `packages/spec` and
`packages/formula` are the spec seat's: the `domain:skills` taker edits
docs and coordinates the spec half as a sibling PR by that seat, ⛔ not a
cross-lane rider」), nothing under `packages/` is touched here; the spec
half is a sibling PR by that seat, tracked as #17849. No ADR is written
— B means there is no phase to define.

Part of #17323

## Acceptance notes

### Premises, re-taken at this branch's base `758ac409`

1. **HOLDS.** `git grep -l 'M9\.[12]' origin/main` returns exactly seven
files — `.changeset/blank-node-condition-refused-at-registration.md` (1
hit), `.changeset/flow-edge-condition-evaluated-slot.md` (3 hits),
`content/docs/data-modeling/formulas.mdx` (1 hit),
`packages/formula/src/cel-engine.ts`,
`packages/formula/src/normalize.ts`, `packages/spec/CHANGELOG.md`,
`packages/spec/src/shared/expression.zod.ts`. The last four are the spec
seat's and are untouched here; after this PR the repo-wide count is
those four and nothing else.
2. **HOLDS, with a timing note.** Both changesets are present and
unconsumed under `.changeset/` at this base. ⚠️ The standing Version
Packages PR #17076 (`changeset-release/main`, bot-authored) lists both
of them as `removed` — it is the consuming side. So this correction has
to land **before** that PR does; once a release consumes these files,
the ruling's item 3 routes the same correction to a `CHANGELOG.md`
erratum instead, which rides the spec half.
3. **HOLDS.** `formulas.mdx` :27 (`deleted in M9`), :111 (`M9.9b`) and
:583 (`M9.5`) are other milestone references and are byte-identical —
they do not appear in the diff, and `git grep -c 'M9' --
content/docs/data-modeling/formulas.mdx` still reports 3 (now at :27 /
:112 / :584, shifted by the one line this PR adds).
4. **HOLDS.** All 22 open PRs' file lists were re-scanned; none names
the three files, with the single qualification in premise 2 — #17076
lists the two changesets as consumed, which is not a competing edit.

### The sentences, before → after

**A · `content/docs/data-modeling/formulas.mdx` :86-87**

```
- artifact always contains the full envelope (and, after M9.2, the AST).
+ artifact always contains the full envelope: `source` is the canonical persisted
+ form, and `ast` is an optional opaque structured value.
```

**B1 · `.changeset/flow-edge-condition-evaluated-slot.md` :30** — inside
the blockquote that reproduces the refusal sentence:

```
- > engine evaluates `source` (the canonical persisted form of phase M9.1) and
+ > engine evaluates `source` (the canonical persisted form) and
```

**B2 · `.changeset/flow-edge-condition-evaluated-slot.md` :44-48** — the
phase-2 promise itself:

```
-   the persistence contract (`source` OR `ast`), whose docblock declares that
-   `ast` becomes required in build output at phase M9.2. When AST-only
-   evaluation lands, `EvaluatedExpressionSchema` is the one place to relax, and
-   every evaluated slot follows.
+   the persistence contract (`source` OR `ast`), where `ast` is accepted as an
+   optional opaque structured value and carries no promise of becoming required.
+   If AST-only evaluation is ever chartered, `EvaluatedExpressionSchema` is the
+   one place to relax, and every evaluated slot follows.
```

**B3 · `.changeset/flow-edge-condition-evaluated-slot.md` :73**

```
- carried only `ast` has no evaluable form under M9.1: author its `source`. A
+ carried only `ast` has no evaluable form: author its `source`. A
```

**C · `.changeset/blank-node-condition-refused-at-registration.md` :33**
— the eighth site, which neither the card nor the ruling named. **What
it said:** the same verbatim blockquote of the refusal sentence that B1
carries, with the identical `(the canonical persisted form of phase
M9.1)` parenthetical; it is the only M9 reference in that file, and it
gets the identical treatment:

```
- > engine evaluates `source` (the canonical persisted form of phase M9.1) and
+ > engine evaluates `source` (the canonical persisted form) and
```

Nothing else in the three files is touched: 3 files, 9 insertions, 8
deletions, and the changeset frontmatter (package and bump level) of
both changesets is unchanged.

### D · Verification

| reading | result |
|---|---|
| `git grep -l 'M9\.[12]' -- content .changeset` | 0 files (exit 1, no
match) |
| control — `git grep -c 'M9' --
content/docs/data-modeling/formulas.mdx` | still `3` (the :27 / :112 /
:584 milestones) |
| control — the pattern still matches elsewhere, so it is not a dead
pattern: `git grep -c 'M9\.[12]'` | 4 files, all the spec seat's |
| dark control — `git grep -c 'M91zzz' -- content .changeset` | 0 (exit
1), so the pattern does not match everything |
| `grep -naP` for raw control bytes over the three files | clean (exit
1) |

### Coordination with the spec half, #17849

The blockquote edited in B1 and C is a **verbatim quote of an exported
constant** — `EVALUATED_EXPRESSION_SOURCE_REQUIRED` in
`packages/spec/src/shared/expression.zod.ts`, which still carries `of
phase M9.1` on `main`. This PR drops exactly that phase clause and keeps
`(the canonical persisted form)`, because "`source` is the canonical
persisted form" is the present-tense contract the ruling's item 1 names.
For the quote to stay a quote, the spec half must land that same wording
in the constant. Flagged rather than worked around: `packages/spec` is
not this lane's, per item 4.

### Changeset: `skip-changeset`, measured

Two existing changesets are edited and none is added, so the changeset
count this PR adds is 0 and the label is the applicable rule
(`AGENTS.md` Post-Task Checklist step 3: the label is for a diff that
publishes nothing from any released package). Measured rather than
assumed:

- no published package's `files[]` ships `content/**` or `.changeset/**`
— 0 matching entries across every non-private workspace manifest;
- the added strings (`carries no promise of becoming required`, `is an
optional opaque structured value`) appear in 0 published paths;
- positive control — `canonical persisted form` **does** hit a published
path (`packages/spec/CHANGELOG.md`,
`packages/spec/src/shared/expression.zod.ts`), so the measurement is not
vacuous.

The publication this correction affects is already declared by the two
changesets it edits (`@objectstack/spec` minor,
`@objectstack/service-automation` minor); a third changeset would
declare a release of its own for a prose correction that rides theirs.
The `CHANGELOG.md` erratum for the already-published M9.2 text is the
ruling's item 2 and belongs to the spec half.

### Gates

Derived in this worktree with `node scripts/pm/dispatch-gates.mjs
--commands --repo objectstack-ai/objectstack` (no paths — the tool took
the change set from git itself at `9e12d4a62` vs merge base
`758ac4097`): **51 commands**. Every one was run; reconciliation with
`--ran` reports **51 derived, 51 run, 0 NOT-MEASURED, 0 UNRUN**, all
exit 0.

Four of them first exited `3` / `1` as **PREREQUISITE NOT MET** —
nothing measured, unbuilt workspace packages, not findings:
`check:doc-formula-expressions` and `check:doc-security-posture`
(`@objectstack/formula`, `@objectstack/lint` unbuilt),
`check:docs-transcript-drift` (same), and `check:skill-examples`
(`packages/client-react/dist` held no `.d.ts`). After `pnpm exec turbo
run build --filter='@objectstack/lint...'
--filter='@objectstack/formula' --filter='@objectstack/client-react...'
--concurrency=2`, all four are exit 0. Verdict lines, as each gate
printed them:

```
✓ check-adr-0087-registration: this PR adds no declared-breaking changeset (2 non-breaking changeset(s) seen).
✓ This diff introduces no `major` bump.
✓ No empty-frontmatter changeset introduced by this diff (2 declaring changeset(s) added).
✓ doc authoring guard: 401 files clean — no bare metadata literals.
check-nul-bytes: OK (scanned 8476 text file(s) -- 8476 tracked, 0 untracked-not-ignored; skipped 7 binary; no raw ASCII control bytes).
✓ check:doc-formula-expressions: 22 record-scoped formula example(s) across 438 files / 1374 TS blocks judged clean by @objectstack/formula.
✓ check-docs-transcript-drift: 4 declared transcript value(s) across 402 page(s) under content/docs/ equal what the registry derives today, and no undeclared block quotes one.
```

`node scripts/check-changeset-fixed.mjs` was run as well and is exit 0 —
the derivation flags its roster as living under `.changeset`, one of
this PR's paths, so its silence is evidence in neither direction until
run. It reads `.changeset/config.json` and the workspace manifests,
neither of which this PR touches.

Repo-wide scans (`pnpm lint` and the rest) are CI's, as are the two
path-scheduled CI jobs and the 11 declared-wide families the derivation
names as unplaceable locally.

### Noted, not filed

- `scripts/check-adr-0087-registration.mjs`'s pass line labels every
**skipped** changeset "non-breaking" (`${result.skipped.length}
non-breaking changeset(s) seen`), so the two changesets here — both
declared breaking at base and skipped as inherited stock by the
specified `M breaking at head, already breaking at base` row — are
reported as non-breaking. The verdict is correct and the row is a pinned
self-test case; only the summary wording under-describes. A pass-line
wording nit, not a defect class, not a contract violation and not an
authoring trap, so no card. Taker: none — no queued PR touches that
script.

---
_Generated by [Claude
Code](https://claude.ai/code/session_01MCLBsUgfykL74aU716rzVK)_

Co-authored-by: Claude <noreply@anthropic.com>

Author: claude[bot]

.changeset/blank-node-condition-refused-at-registration.md

@@ -30,7 +30,7 @@ nodes:
 ```
 
 > An expression in an evaluated slot needs a non-blank `source`: the expression
-> engine evaluates `source` (the canonical persisted form of phase M9.1) and
+> engine evaluates `source` (the canonical persisted form) and
 > cannot evaluate `ast` alone, so an envelope carrying only `ast`, or a `source`
 > that is blank after trimming, would validate and register and then fault at
 > run time. Write `{ dialect: 'cel', source: '…' }`.

.changeset/flow-edge-condition-evaluated-slot.md

@@ -27,7 +27,7 @@ edges:
 ```
 
 > An expression in an evaluated slot needs a non-blank `source`: the expression
-> engine evaluates `source` (the canonical persisted form of phase M9.1) and
+> engine evaluates `source` (the canonical persisted form) and
 > cannot evaluate `ast` alone, so an envelope carrying only `ast`, or a `source`
 > that is blank after trimming, would validate and register and then fault at
 > run time. Write `{ dialect: 'cel', source: '…' }`.
@@ -42,10 +42,10 @@ edges:
   `invalid_union` issue at the slot carrying the sentence above; a blank
   `source` inside an envelope surfaces as one `custom` issue at `source`.
 - **`ExpressionSchema` / `ExpressionInputSchema` are NOT narrowed.** They remain
-  the persistence contract (`source` OR `ast`), whose docblock declares that
-  `ast` becomes required in build output at phase M9.2. When AST-only
-  evaluation lands, `EvaluatedExpressionSchema` is the one place to relax, and
-  every evaluated slot follows.
+  the persistence contract (`source` OR `ast`), where `ast` is accepted as an
+  optional opaque structured value and carries no promise of becoming required.
+  If AST-only evaluation is ever chartered, `EvaluatedExpressionSchema` is the
+  one place to relax, and every evaluated slot follows.
 - **`structuralConditionRefusal` no longer admits an `ast`-only envelope** on
   either structural condition slot (`config.condition` on a node,
   `edge.condition`). #15662's refusal admitted it on purpose through a
@@ -70,7 +70,7 @@ edges:
   it. None of them grew a rule of its own.
 
 **What an author does with a refused edge condition.** An edge condition that
-carried only `ast` has no evaluable form under M9.1: author its `source`. A
+carried only `ast` has no evaluable form: author its `source`. A
 whitespace-only condition — envelope or bare string — was never a predicate
 (the engine answered `false`, so that edge never fired): remove the
 `condition` key if the edge was meant to be unconditional, or write the

content/docs/data-modeling/formulas.mdx

@@ -84,7 +84,8 @@ Formatters: `currency[:CODE]`, `number[:decimals]`, `percent[:decimals]`,
 
 At **input** time you may write a bare string for shorthand — the spec
 transforms it into the right envelope based on the field type. The compiled
-artifact always contains the full envelope (and, after M9.2, the AST).
+artifact always contains the full envelope: `source` is the canonical persisted
+form, and `ast` is an optional opaque structured value.
 
 {/* os:check */}
 ```ts