fix(ci): codeql-action v4.38.1 -> v4.38.0 SHA pin + dependabot hold (estate-wide startup_failure) (#92)

## Summary

Estate-wide incident: `github/codeql-action` **v4.38.1** fails GitHub
workflow **startup** on every repo that took it — CodeQL/Hypatia runs
die with `startup_failure`, zero jobs dispatched, no error text in any
API surface. The evidence chain (full detail: **nexia-list#100**):

| repo | ref | status |
|---|---|---|
| nexia-list | `@v4.38.1` tag (via dependabot #94) | 🔴 startup_failure →
fixed by rollback #100 (merged) |
| hypatia | `@1c5b675` (4.38.1 SHA) | 🔴 |
| vexometer | `@v4.38.1` | 🔴 (since Sep-21) |
| rsr-template-repo | `@1c5b675` | 🔴 |
| affinescript / boj-server / deed-ecosystem | ≤ v4.38.0 | ✅ green |

The v4.38.1 tag *exists* (peels to `1c5b675`) and byte-identical
workflow content runs under a fresh path — so the failure is the
**version value itself** at GitHub's start-validation layer, not
content, permissions (probes with `security-events` start fine), or the
default-setup conflict.

## Changes here

- `codeql-reusable.yml`, `hypatia-scan-reusable.yml`: `codeql-action/*`
re-pinned `1c5b675` (v4.38.1) → `b96794f0` (**v4.38.0** commit; wrong `#
v3` comments corrected to `# v4.38.0`).
- `actions.lock`: re-keyed to the v4.38.0 SHA entries (dependabot bumped
the reusable pins without regenerating the lock).
- `dependabot.yml`: **full hold** on `github/codeql-action` — scoped
`versions:` ignores do NOT hold for this bot path (nexia-list#101
re-raised the bump in SHA form within an hour, copying the inline
warning comment verbatim while swapping the SHA).

## Follow-ups

Consumer rollbacks shipped in the same batch: nexia-list (merged ✅),
**hypatia**, **vexometer**, **rsr-template-repo**,
**metadatastician/burble** (each with the same dependabot hold).
Reconsider the hold when upstream clears v4.38.1 or a newer release
verifies green on one canary repo.

Co-authored-by: arena-agent <arena-agent@users.noreply.github.com>

Author: hyperpolymath

.github/dependabot.yml

@@ -15,6 +15,14 @@ updates:
           - "*"
 
   # Rust/Cargo
+    ignore:
+      # HOLD: github/codeql-action at v4.38.0 (SHA-pinned). v4.38.1 fails
+      # GitHub workflow-startup validation estate-wide (nexia-list#100;
+      # SHA-form re-bump bypassed versions-scoped ignores - see
+      # nexia-list#101/#104). Hold until upstream clears 4.38.1 or a
+      # newer release verifies green; revisit deliberately.
+      - dependency-name: "github/codeql-action"
+
   - package-ecosystem: "cargo"
     directory: "/"
     schedule:

.github/workflows/actions.lock

@@ -14,7 +14,7 @@ workflows:
         - 'haskell-actions/setup@v2.12.0'
     '.github/workflows/codeql.yml':
         - 'actions/checkout@v7.0.1'
-        - 'github/codeql-action@v4.38.1'
+        - 'github/codeql-action@b96794f015dfd88f77b49b1c93e0fa7110f94c63'
     '.github/workflows/dependabot-automerge.yml':
         - 'dependabot/fetch-metadata@v3.1.0'
     '.github/workflows/dogfood-gate.yml':
@@ -94,9 +94,9 @@ dependencies:
         commit: 'sha1-54075bcc5e249e4758d363f27d099f55d843f124'
         owner_id: 47606891
         repo_id: 331103973
-    'github/codeql-action@v4.38.1':
-        ref: 'v4.38.1'
-        commit: 'sha1-1c5b675653bb5c22dbe9b12b556ec555138e09fd'
+    'github/codeql-action@b96794f015dfd88f77b49b1c93e0fa7110f94c63':
+        ref: 'b96794f015dfd88f77b49b1c93e0fa7110f94c63'
+        commit: 'sha1-b96794f015dfd88f77b49b1c93e0fa7110f94c63'
         owner_id: 9919
         repo_id: 259445878
     'haskell-actions/setup@v2.12.0':

.github/workflows/codeql.yml

@@ -41,12 +41,12 @@ jobs:
         uses: actions/checkout@v7.0.1
 
       - name: Initialize CodeQL
-        uses: github/codeql-action/init@v4.38.1
+        uses: github/codeql-action/init@b96794f015dfd88f77b49b1c93e0fa7110f94c63 # v4.38.0 (4.38.1 blocked estate-wide; nexia-list#100)
         with:
           languages: ${{ matrix.language }}
           build-mode: ${{ matrix.build-mode }}
 
       - name: Perform CodeQL Analysis
-        uses: github/codeql-action/analyze@v4.38.1
+        uses: github/codeql-action/analyze@b96794f015dfd88f77b49b1c93e0fa7110f94c63 # v4.38.0 (4.38.1 blocked estate-wide; nexia-list#100)
         with:
           category: "/language:${{ matrix.language }}"