feat(ci): add workflow_dispatch to force backward-compat execution

- workflow_dispatch input: force_backward_compat (boolean, default false)
- Path detection now diffs against origin/main (catches multi-commit pushes)
- Set force_backward_compat=true in workflow_dispatch to force the full
  M-AI-01 compatibility test regardless of changed paths

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

.gitea/workflows/deploy.yml

@@ -3,6 +3,12 @@ name: Deploy API Server
 on:
   push:
     branches: [main]
+  workflow_dispatch:
+    inputs:
+      force_backward_compat:
+        description: 'Force M-AI-01 backward compatibility test'
+        type: boolean
+        default: false
 
 env:
   DATABASE_URL: ${{ secrets.DATABASE_URL }}
@@ -114,14 +120,22 @@ jobs:
         id: paths
         run: |
           cd $WORKDIR
-          CHANGED=$(git diff --name-only HEAD~1..HEAD 2>/dev/null || git diff --name-only HEAD~1 2>/dev/null || echo "")
+          FORCE="${{ inputs.force_backward_compat || 'false' }}"
+          if [ "$FORCE" = "true" ]; then
+            echo "[backward-compat] Forced by workflow_dispatch input"
+            echo "run_compat=true" > /tmp/compat-decision
+            exit 0
+          fi
+          # Diff against origin/main to catch all changes in this push
+          git fetch origin main 2>/dev/null || true
+          CHANGED=$(git diff --name-only origin/main...HEAD 2>/dev/null || git diff --name-only HEAD~1..HEAD 2>/dev/null || echo "")
           echo "Changed files: $CHANGED"
           if echo "$CHANGED" | grep -qE "prisma/schema.prisma|prisma/migrations/|src/modules/ai-analysis/|src/workers/ai-analysis.worker.ts|src/infrastructure/queue/|src/infrastructure/outbox/|src/modules/ai-runtime/ai-job"; then
             echo "DB-related changes detected — running backward compatibility"
-            echo "run_compat=true" >> /tmp/compat-decision
+            echo "run_compat=true" > /tmp/compat-decision
           else
             echo "No DB-related changes — skipping backward compatibility"
-            echo "run_compat=false" >> /tmp/compat-decision
+            echo "run_compat=false" > /tmp/compat-decision
           fi
 
       - name: Ensure infrastructure