fix(#2128): address review — migrate 9 mis-allowlisted sites, harden scanner + guards

Correctness review of the Phase 4 guard found the allowlist over-broad and the
scanner/guards evadable. Fixed all findings:

- Migrate 9 sites that were wrongly sanctioned: their regex is the PURE canonical
  token (`\d+[A-Z]?(?:\.\d+)*`, no variant), byte-identical to already-migrated
  siblings. The old justification argued against swapping to the extractPhaseToken()
  FUNCTION (behavior-risky) — but the guard only wants the same regex built from
  the SOURCE string (byte-equal, zero risk). Coverage is now 32 migrated / 5
  sanctioned, not the overstated 23 / 14 (audit.cts x3, uat.cts, init.cts x4,
  roadmap-upgrade.cts). Each conversion proven byte-equal (.source + .flags).
- Harden the drift detector: also catch the `[0-9]`-in-place-of-`\d` variant;
  document the accepted limits (cross-line split, semantic restructuring —
  covered by the identity guard + review, not a text scan).
- Sanction robustness: a `phase-id-owner:` marker now counts only inside a `//`
  comment (a bare substring in a string no longer suppresses a real flag), and
  the preceding-line window skips blank lines (an auto-formatter's blank line no
  longer reactivates the flag).
- roadmap-parser.cts:462 comment: corrected — that regex carries no /i flag, so
  its [A-Za-z] class does real case work (matches state.cts:1409's rationale).
- Identity guard: surface require failures instead of silently skipping, and
  floor coverage at >75% of consumer modules (inspects 156/157).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/audit.cts

@@ -20,6 +20,9 @@ const { planningDir } = planningWorkspace;
 // eslint-disable-next-line @typescript-eslint/no-require-imports
 import frontmatter = require('./frontmatter.cjs');
 const { extractFrontmatter } = frontmatter;
+// eslint-disable-next-line @typescript-eslint/no-require-imports
+import phaseIdMod = require('./phase-id.cjs');
+const { PHASE_NUMBER_TOKEN_SOURCE } = phaseIdMod;
 import { requireSafePath, sanitizeForDisplay } from './security.cjs';
 
 // ─── Types ────────────────────────────────────────────────────────────────────
@@ -482,8 +485,7 @@ function scanUatGaps(planDir: string): UatGapItem[] {
 
   for (const dir of dirs) {
     const phaseDir = path.join(phasesDir, dir);
-    // phase-id-owner: cosmetic phase label derived from a dir name for JSON output; the single-segment capture is not equivalent to extractPhaseToken dash-continuation semantics, so not a behavior-preserving drop-in.
-    const phaseMatch = dir.match(/^(\d+[A-Z]?(?:\.\d+)*)/i);
+    const phaseMatch = dir.match(new RegExp(`^(${PHASE_NUMBER_TOKEN_SOURCE})`, 'i'));
     const phaseNum = phaseMatch ? phaseMatch[1] : dir;
 
     let files: string[];
@@ -553,8 +555,7 @@ function scanVerificationGaps(planDir: string): VerificationGapItem[] {
 
   for (const dir of dirs) {
     const phaseDir = path.join(phasesDir, dir);
-    // phase-id-owner: cosmetic phase label derived from a dir name for JSON output; the single-segment capture is not equivalent to extractPhaseToken dash-continuation semantics, so not a behavior-preserving drop-in.
-    const phaseMatch = dir.match(/^(\d+[A-Z]?(?:\.\d+)*)/i);
+    const phaseMatch = dir.match(new RegExp(`^(${PHASE_NUMBER_TOKEN_SOURCE})`, 'i'));
     const phaseNum = phaseMatch ? phaseMatch[1] : dir;
 
     let files: string[];
@@ -616,8 +617,7 @@ function scanContextQuestions(planDir: string): ContextQuestionItem[] {
 
   for (const dir of dirs) {
     const phaseDir = path.join(phasesDir, dir);
-    // phase-id-owner: cosmetic phase label derived from a dir name for JSON output; the single-segment capture is not equivalent to extractPhaseToken dash-continuation semantics, so not a behavior-preserving drop-in.
-    const phaseMatch = dir.match(/^(\d+[A-Z]?(?:\.\d+)*)/i);
+    const phaseMatch = dir.match(new RegExp(`^(${PHASE_NUMBER_TOKEN_SOURCE})`, 'i'));
     const phaseNum = phaseMatch ? phaseMatch[1] : dir;
 
     let files: string[];