feat(ledger): резолв несматченных линков ZenMoney↔брокер

GET /links/unmatched, POST /links, DELETE /links/{id}: ручная привязка того,
что ledger/matching.py не смог сопоставить автоматически.

backend/src/fintracker/api/app.py

@@ -23,6 +23,7 @@ from fintracker.api.routers import (
     events,
     health,
     instruments,
+    links,
     metrics,
     networth,
     rules,
@@ -86,6 +87,7 @@ def create_app() -> FastAPI:
     app.include_router(analytics.router, prefix=API_PREFIX)
     app.include_router(events.router, prefix=API_PREFIX)
     app.include_router(instruments.router, prefix=API_PREFIX)
+    app.include_router(links.router, prefix=API_PREFIX)
     app.include_router(metrics.router, prefix=API_PREFIX)
     if settings.web_dir is not None:
         mount_web(app, settings.web_dir, API_PREFIX)