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/features/ocr/api/ocr.routes.ts

@@ -0,0 +1,31 @@
+/**
+ * @ai-summary Fastify routes for OCR API
+ */
+import { FastifyInstance, FastifyPluginAsync, FastifyPluginOptions } from 'fastify';
+import { OcrController } from './ocr.controller';
+
+export const ocrRoutes: FastifyPluginAsync = async (
+  fastify: FastifyInstance,
+  _opts: FastifyPluginOptions
+) => {
+  const ctrl = new OcrController();
+  const requireAuth = fastify.authenticate.bind(fastify);
+
+  // POST /api/ocr/extract - Synchronous OCR extraction
+  fastify.post('/ocr/extract', {
+    preHandler: [requireAuth],
+    handler: ctrl.extract.bind(ctrl),
+  });
+
+  // POST /api/ocr/jobs - Submit async OCR job
+  fastify.post('/ocr/jobs', {
+    preHandler: [requireAuth],
+    handler: ctrl.submitJob.bind(ctrl),
+  });
+
+  // GET /api/ocr/jobs/:jobId - Get job status
+  fastify.get<{ Params: { jobId: string } }>('/ocr/jobs/:jobId', {
+    preHandler: [requireAuth],
+    handler: ctrl.getJobStatus.bind(ctrl),
+  });
+};