feat: add station matching from receipt merchant name (refs #132)

Add Google Places Text Search to match receipt merchant names (e.g.
"Shell", "COSTCO #123") to real gas stations. Backend exposes
POST /api/stations/match endpoint. Frontend calls it after OCR
extraction and pre-fills locationData with matched station's placeId,
name, and address. Users can clear the match in the review modal.

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

backend/src/features/stations/api/stations.controller.ts

@@ -10,6 +10,7 @@ import { pool } from '../../../core/config/database';
 import { logger } from '../../../core/logging/logger';
 import {
   StationSearchBody,
+  StationMatchBody,
   SaveStationBody,
   StationParams,
   UpdateSavedStationBody
@@ -53,6 +54,29 @@ export class StationsController {
     }
   }
   
+  async matchStation(request: FastifyRequest<{ Body: StationMatchBody }>, reply: FastifyReply) {
+    try {
+      const { merchantName } = request.body;
+
+      if (!merchantName || !merchantName.trim()) {
+        return reply.code(400).send({
+          error: 'Bad Request',
+          message: 'Merchant name is required',
+        });
+      }
+
+      const result = await this.stationsService.matchStationFromReceipt(merchantName);
+
+      return reply.code(200).send(result);
+    } catch (error: any) {
+      logger.error('Error matching station from receipt', { error, merchantName: request.body?.merchantName });
+      return reply.code(500).send({
+        error: 'Internal server error',
+        message: 'Failed to match station',
+      });
+    }
+  }
+
   async saveStation(request: FastifyRequest<{ Body: SaveStationBody }>, reply: FastifyReply) {
     try {
       const userId = (request as any).user.sub;