Fix mobile photo upload: resize large camera images + increase body limit

Mobile cameras produce 8-12MB photos. Now:
- Canvas-based resize to max 2000x1500 before upload
- JPEG compression at 0.7-0.85 quality
- Express body limit increased to 5MB for id-upload route
- Falls back to raw upload for small images and PDFs

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

api/src/index.ts

@@ -69,6 +69,8 @@ app.use("/api/v1/webhooks/stripe", express.raw({ type: "application/json" }));
 
 app.use(identityRouter);  // identity webhook uses raw() internally on its specific route
 
+// Photo ID upload needs larger body (resized images up to ~3MB as base64)
+app.use("/api/v1/id-upload", express.json({ limit: "5mb" }));
 app.use(express.json({ limit: "512kb" }));  // 512kb for eSign signature PNG base64
 
 // Reject non-JSON content types on POST/PUT/PATCH