fix(ci): auto-promote gate-check uses workflow file paths, not names

Observed 2026-04-28: auto-promote ran for staging head 96955f7b with
all gates actually green (verified via /commits/<sha>/check-runs API)
yet `check-all-gates-green` reported `CodeQL → missing/none` and
aborted. Same SHA was promotable; auto-promote couldn't see it.

Cause: `gh run list --workflow="CodeQL"` matched two workflows in
this repo:

  - codeql.yml (explicit, scans both staging and main)
  - codeql       (GitHub UI-configured Code-quality default setup,
                  internal, scans default branch only)

gh CLI rejects ambiguous `--workflow=<name>` lookups and returns no
result → the gate fell through to `missing/none` and ALL_GREEN was
set false. Every staging push since both names existed has been
silently dead-locked.

Fix: switch GATES from display-name strings to workflow file paths.
File paths are the unique identifier for a workflow file in
.github/workflows/; display names are decoration and can collide.
The same `gh run list --workflow=<file.yml>` query that fails on
"CodeQL" succeeds on "codeql.yml" because the file path resolves
unambiguously.

No behavior change for the other three gates (CI, E2E Canvas, E2E
API Smoke) since their names didn't collide — they keep working,
they just identify by ci.yml / e2e-staging-canvas.yml / e2e-api.yml
now. The log line shape changes from `CI → completed/success` to
`ci.yml → completed/success` which is fine for ops grep.

When adding/removing a gate going forward: file paths only. Keep
branch-protection required-checks (check-run display names) in
sync as a separate manual step.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

.github/workflows/auto-promote-staging.yml

@@ -61,13 +61,30 @@ jobs:
         run: |
           set -euo pipefail
 
-          # Required gate workflow names. Must match the `name:` field
-          # in the respective .github/workflows/*.yml files.
+          # Required gate workflow files. Use file paths (relative to
+          # .github/workflows/) rather than display names because:
+          #
+          #   1. `gh run list --workflow=<name>` is ambiguous when two
+          #      workflows have the same `name:` — observed 2026-04-28
+          #      with "CodeQL" matching both `codeql.yml` (explicit) and
+          #      GitHub's UI-configured Code-quality default setup
+          #      (internal "codeql"). gh CLI returns "could not resolve
+          #      to a unique workflow" → empty result → gate evaluated
+          #      as missing/none → auto-promote dead-locked despite all
+          #      checks actually passing.
+          #
+          #   2. File paths are the unique identifier for workflows;
+          #      `name:` is just a display string and can collide.
+          #
+          # When adding/removing a gate, update this list AND the
+          # branch-protection required-checks list (which uses check-run
+          # display names, not workflow names; the two are decoupled and
+          # should be kept in sync manually).
           GATES=(
-            "CI"
-            "E2E Staging Canvas (Playwright)"
-            "E2E API Smoke Test"
-            "CodeQL"
+            "ci.yml"
+            "e2e-staging-canvas.yml"
+            "e2e-api.yml"
+            "codeql.yml"
           )
 
           echo "head_sha=${HEAD_SHA}" >> "$GITHUB_OUTPUT"