chore: adopt Corestack project standards

Adopt ADRs-only documentation policy, compact base and Go rules, comment lint and TODO checks.

Always validate records with the local docs checker. Skip implementation CI for root Markdown and docs-only changes while retaining coverage for embedded templates and future modules.

.gitea/workflows/docs-check.yml

@@ -0,0 +1,15 @@
+name: Documentation
+on:
+  push:
+    branches: [main]
+  pull_request:
+jobs:
+  docs:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v7.0.1
+      - uses: actions/setup-go@v7.0.0
+        with:
+          go-version-file: go.mod
+          cache: false
+      - run: go run ./cmd/docs check