chore: configure Python template synchronization

.devcontainer/post-attach.sh

@@ -4,57 +4,4 @@ set -euo pipefail
 repo_root="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
 cd "${repo_root}"
 
-if ! git rev-parse --git-dir >/dev/null 2>&1; then
-  exit 0
-fi
-
-template_remote_url="git@github.com:TECHLETES/python_template.git"
-origin_url="$(git remote get-url origin 2>/dev/null || true)"
-if [[ "${origin_url}" == "${template_remote_url}" ]]; then
-  echo "Current repository is the template; skipping template update check."
-  exit 0
-fi
-
-if ! git remote get-url template >/dev/null 2>&1; then
-  echo "Template remote not configured; adding it."
-  git remote add template "${template_remote_url}"
-  git remote set-url --push template DISABLED
-fi
-
-current_branch="$(git symbolic-ref --quiet --short HEAD || true)"
-if [[ -z "${current_branch}" ]]; then
-  echo "Detached HEAD; skipping template update check."
-  exit 0
-fi
-
-echo "Checking for updates from template/main..."
-if ! git fetch template --prune; then
-  echo "Template update check failed; continuing without updates."
-  exit 0
-fi
-
-if ! git show-ref --verify --quiet refs/remotes/template/main; then
-  echo "Template remote exists but template/main is not available; skipping."
-  exit 0
-fi
-
-ahead_count="$(git rev-list --count HEAD..template/main)"
-if [[ "${ahead_count}" -eq 0 ]]; then
-  echo "Template is up to date."
-  exit 0
-fi
-
-echo "Template has ${ahead_count} new commit(s)."
-
-if [[ -n "$(git status --porcelain=v1)" ]]; then
-  echo "Working tree is dirty; skipping automatic merge from template/main."
-  echo "Review and merge template/main manually when you are ready."
-  exit 0
-fi
-
-echo "Applying template/main without committing; review and commit or abort the merge manually."
-if git merge --no-commit --allow-unrelated-histories --no-ff -m "Merge template/main into ${current_branch}" template/main; then
-  echo "Template updates applied without a commit. Review the staged merge, then commit or abort it manually."
-else
-  echo "Template merge needs manual resolution."
-fi
+echo "Devcontainer attached. Template updates run through the Sync template workflow."

.github/workflows/reconcile-template-sync-branch.yml

@@ -0,0 +1,38 @@
+name: Reconcile template sync branch
+
+on:
+  pull_request:
+    types: [closed]
+    branches: [main]
+
+permissions:
+  contents: write
+
+jobs:
+  reconcile:
+    if: >-
+      github.event.pull_request.merged == true &&
+      github.event.pull_request.head.ref == 'chore/template-sync' &&
+      github.event.pull_request.head.repo.full_name == github.repository
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Check out permanent sync branch
+        uses: actions/checkout@v6
+        with:
+          ref: chore/template-sync
+          fetch-depth: 0
+
+      - name: Reconcile merged template sync
+        shell: bash
+        run: |
+          set -euo pipefail
+
+          git config user.name "github-actions[bot]"
+          git config user.email "41898282+github-actions[bot]@users.noreply.github.com"
+
+          git fetch origin main chore/template-sync
+          git switch chore/template-sync
+          git reset --hard origin/chore/template-sync
+          git merge --no-ff --no-edit origin/main
+          git push origin HEAD:refs/heads/chore/template-sync

.github/workflows/template-sync.yml

@@ -0,0 +1,22 @@
+name: Sync template
+
+on:
+  workflow_dispatch:
+  schedule:
+    - cron: "7 3 * * 1"
+
+jobs:
+  sync:
+    uses: TECHLETES/python_template/.github/workflows/reusable-template-sync.yml@main
+
+    with:
+      template_repository: TECHLETES/python_template
+      template_branch: main
+      target_branch: main
+      sync_branch: chore/template-sync
+      config_path: .template-sync.yml
+      pull_request_title: "chore: sync Python template"
+
+    secrets:
+      app_client_id: ${{ vars.TEMPLATE_SYNC_APP_CLIENT_ID }}
+      app_private_key: ${{ secrets.TEMPLATE_SYNC_APP_PRIVATE_KEY }}

.template-sync.yml

@@ -0,0 +1,43 @@
+source:
+  repository: TECHLETES/python_template
+  branch: main
+
+target:
+  branch: main
+  sync_branch: chore/template-sync
+
+# Copied from TECHLETES/python_template/main:.template-sync.yml on 2026-07-29.
+#
+# The two workflows below are intentionally target-owned: this caller contains
+# this repository's branch values, and reconciliation is implemented locally
+# because the referenced reusable reconciliation workflow does not exist in
+# the current Python template.
+paths:
+  # Github configuration and workflows
+  - .github/workflows/template-sync.yml
+  - .github/workflows/reusable-reconcile-template-sync-branch.yml
+  - .github/workflows/staging-main-check.yml
+  - .github/workflows/ci.yml
+  - .github/workflows/test-devcontainer.yml
+  - .github/workflows/test-pre-commit.yml
+  - .github/workflows/test-python.yml
+  - .github/workflows/labeler.yml
+  - .github/ISSUE_TEMPLATE/**
+  - .github/dependabot.yml
+  - .github/pull_request_template.md
+
+  # Development environment.
+  - .devcontainer/**
+
+  # Python and repository tooling.
+  - .pre-commit-config.yaml
+  - .python-version
+  - .editorconfig
+  - .gitattributes
+  - pyproject.toml
+
+  # Shared quality and security helpers.
+  - scripts/hooks/**
+  - scripts/adopt-template.py
+
+  - docs/*.md