REUSE-WP-0019-T03: add Forgejo Actions workflows (part 2 of prior commit)

The .forgejo/workflows/ files and doc updates described in 4862ed6 didn't
actually get staged there (git add silently skipped them after an earlier
pathspec miss on the already-deleted .gitea file) -- committing them now.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

.forgejo/workflows/ci-smoke.yaml

@@ -0,0 +1,29 @@
+# Canonical CI smoke template (tier 1 routing drill).
+# Copy to: .forgejo/workflows/ci-smoke.yaml in consumer repos.
+name: CI Smoke
+
+on:
+  push:
+    branches:
+      - main
+  workflow_dispatch:
+
+jobs:
+  host-smoke:
+    runs-on: self-hosted
+    steps:
+      - name: Routing probe (host runner)
+        run: |
+          set -eu
+          echo "repository=${GITHUB_REPOSITORY:-unknown}"
+          echo "sha=${GITHUB_SHA:-unknown}"
+          echo "runner=${RUNNER_NAME:-unknown}"
+          uname -a
+
+  container-smoke:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Routing probe (container label)
+        run: |
+          set -eu
+          echo "container-smoke ok for ${GITHUB_REPOSITORY:-unknown}"