Fix Dockerfile COPY syntax and add template placeholder

- Remove shell redirect syntax from COPY (not supported in Docker)
- Add .gitkeep to templates/emails to ensure directory exists

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

Dockerfile

@@ -42,8 +42,8 @@ COPY --from=builder /app/api /app/api
 COPY --from=builder /app/worker /app/worker
 COPY --from=builder /app/admin /app/admin
 
-# Copy templates directory if it exists
-COPY --from=builder /app/templates /app/templates 2>/dev/null || true
+# Copy templates directory
+COPY --from=builder /app/templates /app/templates
 
 # Copy migrations and seeds for production use
 COPY --from=builder /app/migrations /app/migrations