feat: add core OCR API integration (refs #65)

OCR Service (Python/FastAPI):
- POST /extract for synchronous OCR extraction
- POST /jobs and GET /jobs/{job_id} for async processing
- Image preprocessing (deskew, denoise) for accuracy
- HEIC conversion via pillow-heif
- Redis job queue for async processing

Backend (Fastify):
- POST /api/ocr/extract - authenticated proxy to OCR
- POST /api/ocr/jobs - async job submission
- GET /api/ocr/jobs/:jobId - job polling
- Multipart file upload handling
- JWT authentication required

File size limits: 10MB sync, 200MB async
Processing time target: <3 seconds for typical photos

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

backend/src/app.ts

@@ -34,6 +34,7 @@ import { userExportRoutes } from './features/user-export';
 import { userImportRoutes } from './features/user-import';
 import { ownershipCostsRoutes } from './features/ownership-costs';
 import { subscriptionsRoutes, donationsRoutes, webhooksRoutes } from './features/subscriptions';
+import { ocrRoutes } from './features/ocr';
 import { pool } from './core/config/database';
 import { configRoutes } from './core/config/config.routes';
 
@@ -95,7 +96,7 @@ async function buildApp(): Promise<FastifyInstance> {
       status: 'healthy',
       timestamp: new Date().toISOString(),
       environment: process.env['NODE_ENV'],
-      features: ['admin', 'auth', 'config', 'onboarding', 'vehicles', 'documents', 'fuel-logs', 'stations', 'maintenance', 'platform', 'notifications', 'user-profile', 'user-preferences', 'user-export', 'user-import', 'ownership-costs', 'subscriptions', 'donations']
+      features: ['admin', 'auth', 'config', 'onboarding', 'vehicles', 'documents', 'fuel-logs', 'stations', 'maintenance', 'platform', 'notifications', 'user-profile', 'user-preferences', 'user-export', 'user-import', 'ownership-costs', 'subscriptions', 'donations', 'ocr']
     });
   });
 
@@ -105,7 +106,7 @@ async function buildApp(): Promise<FastifyInstance> {
       status: 'healthy',
       scope: 'api',
       timestamp: new Date().toISOString(),
-      features: ['admin', 'auth', 'config', 'onboarding', 'vehicles', 'documents', 'fuel-logs', 'stations', 'maintenance', 'platform', 'notifications', 'user-profile', 'user-preferences', 'user-export', 'user-import', 'ownership-costs', 'subscriptions', 'donations']
+      features: ['admin', 'auth', 'config', 'onboarding', 'vehicles', 'documents', 'fuel-logs', 'stations', 'maintenance', 'platform', 'notifications', 'user-profile', 'user-preferences', 'user-export', 'user-import', 'ownership-costs', 'subscriptions', 'donations', 'ocr']
     });
   });
 
@@ -151,6 +152,7 @@ async function buildApp(): Promise<FastifyInstance> {
   await app.register(subscriptionsRoutes, { prefix: '/api' });
   await app.register(donationsRoutes, { prefix: '/api' });
   await app.register(webhooksRoutes, { prefix: '/api' });
+  await app.register(ocrRoutes, { prefix: '/api' });
   await app.register(configRoutes, { prefix: '/api' });
 
   // 404 handler