fix: base first-push validation on dev

Issue: #165
User-Visible: no

.github/workflows/validate.yml

@@ -37,8 +37,9 @@ jobs:
           BEFORE_SHA: ${{ github.event.before }}
           BASE_SHA: ${{ github.event.pull_request.base.sha }}
           HEAD_SHA: ${{ github.sha }}
-          DEFAULT_BRANCH: ${{ github.event.repository.default_branch }}
+          DEVELOPMENT_BRANCH: dev
         run: |
+          git fetch -q origin "refs/heads/$DEVELOPMENT_BRANCH:refs/remotes/origin/$DEVELOPMENT_BRANCH"
           node scripts/validate-commit-provenance.mjs --check-hook-mode --github-range
 
   # Догоняющая проверка процесса (PROCESS.md §10.3). Хуки ловят нарушение на
@@ -59,11 +60,12 @@ jobs:
           BEFORE_SHA: ${{ github.event.before }}
           BASE_SHA: ${{ github.event.pull_request.base.sha }}
           HEAD_SHA: ${{ github.sha }}
-          DEFAULT_BRANCH: ${{ github.event.repository.default_branch }}
+          DEVELOPMENT_BRANCH: dev
           TARGET_REF: ${{ github.ref }}
           # Публичный репозиторий: штатного токена хватает на чтение issue.
           GH_TOKEN: ${{ github.token }}
         run: |
+          git fetch -q origin "refs/heads/$DEVELOPMENT_BRANCH:refs/remotes/origin/$DEVELOPMENT_BRANCH"
           node scripts/process-gate.mjs --github-range --issues
 
   # Классификация изменённых путей: тяжёлые job идут только там, где менялось