go2rtc: auto-reconcile streams so live/recording self-heal

Live and recording both read from the go2rtc restream. If go2rtc's
runtime stream table gets emptied (camera clear via API, go2rtc restart
with a stale/empty config, or a silently-failed startup sync_all), every
restream returns 404 and both live and recording go dark until a manual
`docker restart nvr-go2rtc`.

Add a background Reconciler that every 30s diffs the desired streams
against go2rtc /api/streams and PUTs only the missing ones (existing
streams are left untouched so active producers/consumers are not
disrupted). VERSION -> 0.0.115.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

backend/app/runtime.py

@@ -9,6 +9,7 @@ if TYPE_CHECKING:
     from .recorder.indexer import Indexer
     from .recorder.supervisor import Supervisor
     from .services.retention import Retention
+    from .services.go2rtc import Reconciler
     from .api.ws import ConnectionManager
 
 
@@ -18,6 +19,7 @@ class Runtime:
     supervisor: "Supervisor"
     indexer: "Indexer"
     retention: "Retention"
+    reconciler: "Reconciler"
     ws: "ConnectionManager"