process: derived artifacts are accepted on dev once per beta (#697)

The screenshot fingerprint and golden baselines stop being a tax on every
task branch:

- Task branches no longer commit docs/images/** or golden baselines. On a
  branch the screenshot freshness stays a preflight warning; the review
  prompt, REVIEWER.md and AUTHOR.md drop check-docs as a per-task gate.
- beta-derived.yml refreshes them on dev in one bot commit before the beta
  candidate: canonical docs capture + docs:accept --reviewed, golden from
  the golden-images artifact of a completed Validate on dev +
  golden:accept --reviewed. A changed frame or scene is accepted only when
  named in the inputs; undeclared differences refuse. Baseline commits carry
  Release: and Baseline-Reviewed:; the subject is not a candidate subject.
- classify-changes: the Release: trailer on an issue/* branch no longer
  switches on the heavy set. ci:full / ci:golden do: process-track emits
  full=true, the review gate dispatches Validate with full=true and does not
  accept a light proof.

Canon: PROCESS.md §3 п.13, §5.1, §8, §11.4; CONTRIBUTING.md.

Issue: #697
User-Visible: no
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_018qZfe7YS4rqEMKoVeS3GKd

.github/workflows/validate.yml

@@ -84,6 +84,8 @@ jobs:
           EVENT_NAME: ${{ github.event_name }}
           HEAD_MESSAGE: ${{ github.event.head_commit.message }}
           FULL_INPUT: ${{ inputs.full }}
+          # #697: на ветке задачи `Release:` строгий режим не включает.
+          REF_NAME: ${{ github.ref_name }}
         run: |
           # #586: CLI отдаёт ОДИН ответ. Прежде здесь сравнивался со строкой
           # `heavy=true` весь вывод `--heavy`, а он двухстрочный: в `$(…)`
@@ -282,7 +284,8 @@ jobs:
       # предыдущего пуша штатно, и на #86 (r5) это дало зелёный статус ветки
       # без единого исполненного тяжёлого гейта.
       # Смоки, golden, performance_smoke — на кандидате беты (трейлер
-      # `Release:`), по `workflow_dispatch full=true`, на PR (#479). Логика и
+      # `Release:` вне веток задач, #697), по `workflow_dispatch full=true`, на
+      # PR (#479). Логика и
       # её тест — scripts/classify-changes.mjs.
       - id: heavy
         env:
@@ -290,6 +293,7 @@ jobs:
           HEAD_MESSAGE: ${{ github.event.head_commit.message }}
           FULL_INPUT: ${{ inputs.full }}
           MUTANTS_INPUT: ${{ inputs.mutants }}
+          REF_NAME: ${{ github.ref_name }}
         run: node scripts/classify-changes.mjs --heavy | tee -a "$GITHUB_OUTPUT"
       - id: base
         if: github.event_name != 'pull_request'