feat: add frontend manual extraction flow with review screen (refs #136)

- Create useManualExtraction hook: submit PDF to OCR, poll job status, track progress
- Create useCreateSchedulesFromExtraction hook: batch create maintenance schedules from extraction
- Create MaintenanceScheduleReviewScreen: dialog with checkboxes, inline editing, batch create
- Update DocumentForm: remove "(Coming soon)", trigger extraction after upload, show progress
- Add 12 unit tests for review screen (rendering, selection, empty state, errors)

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

frontend/src/features/maintenance/hooks/useCreateSchedulesFromExtraction.ts

@@ -0,0 +1,41 @@
+/**
+ * @ai-summary Hook for batch-creating maintenance schedules from manual extraction results
+ * @ai-context Maps extracted MaintenanceScheduleItem[] to CreateScheduleRequest[] and creates via API
+ */
+
+import { useMutation, useQueryClient } from '@tanstack/react-query';
+import { maintenanceApi } from '../api/maintenance.api';
+import type { CreateScheduleRequest, MaintenanceScheduleResponse } from '../types/maintenance.types';
+import type { MaintenanceScheduleItem } from '../../documents/hooks/useManualExtraction';
+
+interface CreateSchedulesParams {
+  vehicleId: string;
+  items: MaintenanceScheduleItem[];
+}
+
+export function useCreateSchedulesFromExtraction() {
+  const queryClient = useQueryClient();
+
+  return useMutation<MaintenanceScheduleResponse[], Error, CreateSchedulesParams>({
+    mutationFn: async ({ vehicleId, items }) => {
+      const results: MaintenanceScheduleResponse[] = [];
+      for (const item of items) {
+        const request: CreateScheduleRequest = {
+          vehicleId,
+          category: 'routine_maintenance',
+          subtypes: item.subtypes.length > 0 ? item.subtypes : [],
+          scheduleType: 'interval',
+          intervalMiles: item.intervalMiles ?? undefined,
+          intervalMonths: item.intervalMonths ?? undefined,
+        };
+        const created = await maintenanceApi.createSchedule(request);
+        results.push(created);
+      }
+      return results;
+    },
+    onSuccess: (_data, variables) => {
+      queryClient.invalidateQueries({ queryKey: ['maintenanceSchedules', variables.vehicleId] });
+      queryClient.invalidateQueries({ queryKey: ['maintenanceUpcoming', variables.vehicleId] });
+    },
+  });
+}