fix(ui): Show city from fingerprint data in worker dashboard

City was captured in preflight fingerprint JSON but not displayed.
Now falls back to fingerprint.detectedLocation.city if current_city is null.

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

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

cannaiq/src/pages/WorkersDashboard.tsx

@@ -343,7 +343,8 @@ function PreflightSummary({ worker }: { worker: Worker }) {
   const httpError = worker.preflight_http_error;
   const httpMs = worker.preflight_http_ms;
   const geoState = worker.current_state;
-  const geoCity = worker.current_city;
+  // City from current_city column, or fallback to fingerprint detected location
+  const geoCity = worker.current_city || fingerprint?.detectedLocation?.city;
 
   // Build detailed tooltip
   const tooltipLines: string[] = [];