chore: initial bootstrap — 5 reusable workflows + scaffolding

Public-readable Tier-1 exception (alongside sporel-meta) for the
practical reason that community pipelines need to call into these
workflows without per-repo deploy-token setup.

5 reusable workflows moved from sporel-meta/.gitea/workflows/ to here
(Plan-B.1: privacy-fix for sporel-meta which stays private with the
proprietary design docs).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

.gitea/workflows/reusable-lua.yml

@@ -0,0 +1,70 @@
+# Reusable workflow: Lua-Lib / Module (Cat 3 per ADR-0025)
+# luacheck + JSON validation + on-tag zip
+name: Lua CI
+
+on:
+  workflow_call:
+    inputs:
+      lint_target:
+        description: "Path glob to lint (default: lua/ + init.lua + scripts/)"
+        type: string
+        default: "lua/ scripts/ init.lua"
+
+jobs:
+  lint:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Install luacheck
+        run: |
+          sudo apt-get update -qq
+          sudo apt-get install -y luarocks
+          sudo luarocks install luacheck
+
+      - name: Run luacheck
+        run: |
+          luacheck ${{ inputs.lint_target }} --no-unused-args --no-self || \
+            (echo "::error::luacheck failures" && exit 1)
+
+      - name: Manifest validation
+        shell: bash
+        run: |
+          for manifest in manifest.module manifest.core lib.json; do
+            if [ -f "$manifest" ]; then
+              python3 -c "import json; json.load(open('$manifest'))" || \
+                (echo "::error::$manifest invalid JSON" && exit 1)
+              echo "$manifest: valid JSON"
+            fi
+          done
+          if [ -f dependencies.json ]; then
+            python3 -c "import json; d=json.load(open('dependencies.json')); assert 'required' in d or 'suggests' in d"
+          fi
+
+      - name: README presence (per ADR-0026)
+        run: |
+          test -s README.md || (echo "::error::README.md missing or empty" && exit 1)
+
+      - name: LICENSE presence (per ADR-0027)
+        run: |
+          test -s LICENSE || (echo "::error::LICENSE missing or empty" && exit 1)
+
+  package:
+    needs: lint
+    if: startsWith(github.ref, 'refs/tags/')
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Package as zip
+        run: |
+          ARTEFACT="${GITHUB_REPOSITORY##*/}-${GITHUB_REF_NAME}.zip"
+          zip -r "$ARTEFACT" . -x "*.git/*" -x "*.gitea/*" -x "tests/*"
+          echo "ARTEFACT_NAME=$ARTEFACT" >> "$GITHUB_ENV"
+
+      - name: Upload to Gitea Release
+        uses: akkuman/gitea-release-action@v1
+        with:
+          files: ${{ env.ARTEFACT_NAME }}