fix: generate route tree in CI and Docker build

Ensures routeTree.gen.ts is always fresh so stale checked-in copies
don't break the frontend build or lint.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Dockerfile.frontend

@@ -16,6 +16,7 @@ COPY packages/admin ./packages/admin
 COPY package.json ./
 COPY tsconfig.base.json ./
 WORKDIR /app/packages/admin
+RUN bunx @tanstack/router-cli generate
 RUN bun run build
 
 FROM nginx:alpine