fix: resolve 20 Sentry issues and fix navbar test flakiness

Sentry fixes:
- Only send 5xx errors to Sentry (was sending 4xx rate-limit, media type errors)
- Encode non-ASCII chars in X-Output-Filename header (encodeURIComponent)
- Handle FK constraint failures gracefully in file upload, pipeline save, API keys
- Harden getDirSize against ENOENT race on readdirSync

Test fixes:
- Wrap navbar test renders in act() to flush async useEffect state updates
- Add useEffect cleanup to navbar to prevent state updates on unmounted component
- Fixes timeout when running in full test suite

apps/api/src/index.ts

@@ -100,7 +100,9 @@ app.setErrorHandler((error: Error & { statusCode?: number }, request, reply) =>
     { err: error, url: request.url, method: request.method },
     "Unhandled request error",
   );
-  captureException(error, request);
+  if (statusCode >= 500) {
+    captureException(error, request);
+  }
   const isProduction = process.env.NODE_ENV === "production";
   reply.status(statusCode).send({
     error: statusCode >= 500 ? "Internal server error" : error.message,