Add Gitea webhook auto-deploy: webhook receiver plus server.js proxy route

Dockerfile.frontend

@@ -1,17 +1,10 @@
 # Frontend: Node.js static file server with API proxy
-FROM nfqlt/node20 AS builder
-
-ARG VERSION
-
-# Copy dist to a versioned path — VERSION changes = different path = cache miss
-COPY dist/ /tmp/dist-v${VERSION}/
-
 FROM nfqlt/node20
 
 WORKDIR /app
 
-# Copy from the versioned path (never cached because path changes with VERSION)
-COPY --from=builder /tmp/dist-v${VERSION}/ /app/dist/
+# Copy dist from local build (built on NAS host before docker-compose)
+COPY dist/ /app/dist/
 
 COPY server.js /app/server.js