feat(F-055): completed feature

work/artifacts/F-055/security.json

@@ -0,0 +1,25 @@
+{
+  "feature_id": "F-055",
+  "stage": "security_gate",
+  "agent": "security",
+  "ts": "2026-08-19T11:48:40Z",
+  "verdict": "APPROVED",
+  "checks": [
+    {
+      "name": "no_path_traversal_in_static",
+      "status": "PASS",
+      "detail": "static files served from public/uploads/<size>/<filename>; UUID-based filenames cannot escape"
+    },
+    {
+      "name": "no_secrets_in_thumbnails",
+      "status": "PASS",
+      "detail": "Thumbnails are pure image data, no metadata preserved"
+    },
+    {
+      "name": "sharp_processing_isolated",
+      "status": "PASS",
+      "detail": "sharp only reads image bytes and writes under thumbs/<width>/; no FS traversal beyond input filename"
+    }
+  ],
+  "notes": "Static serving preserves the existing security model. No new attack surface."
+}