fix(ci): add mc#664 tracker comments to all Phase 3 CoE directives

The Tier 2e lint (lint-continue-on-error-tracking, PR #689) requires
every `continue-on-error: true` to carry a `# mc#NNNN` or `# internal#NNNN`
tracker comment within ±2 lines. mc#664 is 0 days old and open — use it
for all Phase 3 interim masks in ci.yml.

Violations fixed:
- canvas-deploy-reminder (line 378): Phase 3 interim, removed when
  platform-build is clean (same cadence as platform-build itself).
- all-required sentinel (line 546): Phase 3 safety, removed when Phase 3
  ends and sentinel hard-fails as designed.

Other workflow files also have violations (37 total across 47 files) —
those are pre-existing and masked by their own `continue-on-error: true`
Phase 3 flags. Each will be triaged in sequence.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

.gitea/workflows/ci.yml

@@ -372,7 +372,10 @@ jobs:
   canvas-deploy-reminder:
     name: Canvas Deploy Reminder
     runs-on: ubuntu-latest
-    continue-on-error: true
+    # Phase 3 interim: mc#664 trackers on all CoE directives. mc#664 fix-forward
+    # (PR #669) re-masks platform-build pending test fixes. Remove CoE once
+    # platform-build is clean.
+    continue-on-error: true  # mc#664
     needs: [changes, canvas-build]
     # Only fires on direct pushes to main (i.e. after staging→main promotion).
     if: needs.changes.outputs.canvas == 'true' && github.event_name == 'push' && github.ref == 'refs/heads/main'
@@ -540,7 +543,7 @@ jobs:
     # still in Phase 3 (continue-on-error: true suppresses their status to null).
     # When Phase 3 ends (defects fixed, continue-on-error flipped off on build
     # jobs), remove continue-on-error here so the sentinel again hard-fails.
-    continue-on-error: true
+    continue-on-error: true  # mc#664 interim — remove when Phase 3 ends
     runs-on: ubuntu-latest
     timeout-minutes: 1
     needs: