feat: re-run and delete scan from detail page

Backend:
- DELETE /api/v1/scans/{id} — 204 on success, 404 if missing,
  409 if pending/running; CASCADE removes routes and flights

Frontend (api.ts):
- scanApi.delete(id)

Frontend (ScanDetails.tsx):
- Re-run button: derives window_months from stored dates, detects
  country vs airports mode via comma in scan.country, creates new
  scan and navigates to it; disabled while scan is active
- Delete button: inline two-step confirm (no modal), navigates to
  dashboard on success; disabled while scan is active

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

flight-comparator/api_server.py

@@ -1337,6 +1337,42 @@ async def get_scan_status(scan_id: int):
         )
 
 
+@router_v1.delete("/scans/{scan_id}", status_code=204)
+async def delete_scan(scan_id: int):
+    """
+    Delete a scan and all its associated routes and flights (CASCADE).
+    Returns 409 if the scan is currently running or pending.
+    """
+    try:
+        conn = get_connection()
+        cursor = conn.cursor()
+
+        cursor.execute("SELECT status FROM scans WHERE id = ?", (scan_id,))
+        row = cursor.fetchone()
+
+        if not row:
+            conn.close()
+            raise HTTPException(status_code=404, detail=f"Scan not found: {scan_id}")
+
+        if row[0] in ('pending', 'running'):
+            conn.close()
+            raise HTTPException(
+                status_code=409,
+                detail="Cannot delete a scan that is currently pending or running."
+            )
+
+        cursor.execute("DELETE FROM scans WHERE id = ?", (scan_id,))
+        conn.commit()
+        conn.close()
+
+        logging.info(f"Scan {scan_id} deleted")
+
+    except HTTPException:
+        raise
+    except Exception as e:
+        raise HTTPException(status_code=500, detail=f"Failed to delete scan: {str(e)}")
+
+
 @router_v1.get("/scans/{scan_id}/routes", response_model=PaginatedResponse[Route])
 async def get_scan_routes(
     scan_id: int,

flight-comparator/frontend/src/api.ts

@@ -123,6 +123,8 @@ export const scanApi = {
     if (destination) params.destination = destination;
     return api.get<PaginatedResponse<Flight>>(`/scans/${id}/flights`, { params });
   },
+
+  delete: (id: number) => api.delete(`/scans/${id}`),
 };
 
 export const airportApi = {

flight-comparator/frontend/src/pages/ScanDetails.tsx

@@ -13,6 +13,8 @@ import {
   MapPin,
   AlertCircle,
   Loader2,
+  RotateCcw,
+  Trash2,
 } from 'lucide-react';
 import { scanApi } from '../api';
 import type { Scan, Route, Flight } from '../api';
@@ -45,6 +47,9 @@ export default function ScanDetails() {
   const [expandedRoute, setExpandedRoute] = useState<string | null>(null);
   const [flightsByDest, setFlightsByDest] = useState<Record<string, Flight[]>>({});
   const [loadingFlights, setLoadingFlights] = useState<string | null>(null);
+  const [rerunning, setRerunning]           = useState(false);
+  const [confirmDelete, setConfirmDelete]   = useState(false);
+  const [deleting, setDeleting]             = useState(false);
 
   useEffect(() => {
     if (id) loadScanDetails();
@@ -110,6 +115,45 @@ export default function ScanDetails() {
     }
   };
 
+  const handleRerun = async () => {
+    if (!scan) return;
+    setRerunning(true);
+    try {
+      // Compute window from stored dates so the new scan covers the same span
+      const ms = new Date(scan.end_date).getTime() - new Date(scan.start_date).getTime();
+      const window_months = Math.max(1, Math.round(ms / (1000 * 60 * 60 * 24 * 30)));
+
+      // country column holds either "IT" or "BRI,BDS"
+      const isAirports = scan.country.includes(',');
+      const resp = await scanApi.create({
+        origin: scan.origin,
+        window_months,
+        seat_class: scan.seat_class as 'economy' | 'premium' | 'business' | 'first',
+        adults: scan.adults,
+        ...(isAirports
+          ? { destinations: scan.country.split(',') }
+          : { country: scan.country }),
+      });
+      navigate(`/scans/${resp.data.id}`);
+    } catch {
+      // silently fall through — the navigate won't happen
+    } finally {
+      setRerunning(false);
+    }
+  };
+
+  const handleDelete = async () => {
+    if (!scan) return;
+    setDeleting(true);
+    try {
+      await scanApi.delete(scan.id);
+      navigate('/');
+    } catch {
+      setDeleting(false);
+      setConfirmDelete(false);
+    }
+  };
+
   const SortIcon = ({ field }: { field: typeof sortField }) => {
     if (sortField !== field) return <ChevronUp size={14} className="opacity-30" />;
     return sortDirection === 'asc'
@@ -203,6 +247,49 @@ export default function ScanDetails() {
             Created {formatDate(scan.created_at)}
           </p>
         )}
+
+        {/* Row 4: actions */}
+        <div className="mt-4 pt-4 border-t border-outline flex items-center justify-end gap-2">
+          {/* Re-run */}
+          <button
+            onClick={handleRerun}
+            disabled={rerunning || isActive}
+            className="inline-flex items-center gap-1.5 px-3 py-1.5 text-sm font-medium rounded-xs border border-outline text-on-surface hover:bg-surface-2 disabled:opacity-40 disabled:cursor-not-allowed transition-colors"
+          >
+            <RotateCcw size={14} className={rerunning ? 'animate-spin' : ''} />
+            {rerunning ? 'Starting…' : 'Re-run'}
+          </button>
+
+          {/* Delete — inline confirm */}
+          {confirmDelete ? (
+            <div className="inline-flex items-center gap-1.5">
+              <span className="text-sm text-on-surface-variant">Delete this scan?</span>
+              <button
+                onClick={handleDelete}
+                disabled={deleting}
+                className="inline-flex items-center gap-1 px-3 py-1.5 text-sm font-medium rounded-xs bg-error text-white hover:bg-error/90 disabled:opacity-60 transition-colors"
+              >
+                {deleting ? 'Deleting…' : 'Yes, delete'}
+              </button>
+              <button
+                onClick={() => setConfirmDelete(false)}
+                disabled={deleting}
+                className="px-3 py-1.5 text-sm font-medium rounded-xs border border-outline text-on-surface hover:bg-surface-2 transition-colors"
+              >
+                Cancel
+              </button>
+            </div>
+          ) : (
+            <button
+              onClick={() => setConfirmDelete(true)}
+              disabled={isActive}
+              className="inline-flex items-center gap-1.5 px-3 py-1.5 text-sm font-medium rounded-xs border border-error/40 text-error hover:bg-error/5 disabled:opacity-40 disabled:cursor-not-allowed transition-colors"
+            >
+              <Trash2 size={14} />
+              Delete
+            </button>
+          )}
+        </div>
       </div>
 
       {/* ── Stat cards ────────────────────────────────────────────── */}