feat(ci): add tools/check.sh test suite + PR CI (build=render, test=check)

Prereqs for autopilot full-auto-merge eligibility (and useful CI on their own):
- tools/check.sh: dependency-light test suite (lab py-compile, sh/json/yaml parse,
  no-em-dash slop guard, per-module template-section structure check). Exits non-zero
  on any failure. The autopilot review gate runs this as its `test` command.
- .gitea/.github workflows/ci.yml: run on every PR + push on the docker runners;
  build = render the wiki from the tree, test = tools/check.sh. The PR commit status
  is what the autopilot gate's CI precondition reads.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01TfzV5QvtPDz8LJS3Pu5VLT

.github/workflows/ci.yml

@@ -0,0 +1,25 @@
+# PR + push CI for the GitHub mirror. Mirrors .gitea/workflows/ci.yml:
+#   build = render the wiki from this tree; test = tools/check.sh.
+name: CI
+on:
+  pull_request: {}
+  push:
+    branches: [main]
+  workflow_dispatch: {}
+
+jobs:
+  check:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-python@v5
+        with:
+          python-version: '3.x'
+      - name: build (render wiki) + test (check.sh)
+        shell: bash
+        run: |
+          set -euo pipefail
+          python3 -m pip install --quiet pyyaml || true
+          python3 tools/build_wiki.py --repo-root . --out /tmp/awc-wiki-build \
+            --web-base https://github.com/justin/ai-workflow-course --branch main --host github
+          bash tools/check.sh