fix(phase1): fix race condition, path traversal, double processing, validation in photo API

.claude/settings.local.json

@@ -81,7 +81,9 @@
       "Bash(git check-ignore *)",
       "Bash(python -m pytest backend/tests/test_schema.py -v)",
       "Bash(awk '{print $NF}')",
-      "Bash(python *)"
+      "Bash(python *)",
+      "Bash(grep -E \"\\\\.\\(py|ts\\)$\")",
+      "Bash(grep -E \"\\\\.py$\")"
     ]
   }
 }