Live ops wall + pluggable camera providers with licence gating (server-26#198)

Backend (c2-core):
- app/internal/cameras/: provider interface, licence model, per-provider
  catalog cache; one adapter per source in design-canvas/camera-sources.md.
  Implemented: 511NY (legacy shape + tolerant XML inventory parser, 511x
  endpoints UNVERIFIED), Caltrans, DelDOT, Ontario 511, DriveBC, Calgary,
  TfL, NSW, Fintraffic. Stubs: NYC DOT, Westchester DPW, TRANSCOM, CTroads,
  511NJ, Austin, TxDOT, MD CHART, WSDOT, Tallinn, Tarktee, Warendorf,
  TrafficLand, Windy, EarthCam.
- Every provider defaults OFF (config/camera_providers). Gated licences
  (agreement required / unverified / non-commercial / paid) need an explicit
  acknowledgement stored with who/when and written to audit_log; the audit
  write is a precondition. Stubs and prohibited sources cannot be enabled.
  Ack is bound to the licence status it was given for.
- GET /cameras (signed-in), GET/PUT /admin/camera-providers (admin only).
- /traffic/511 follows the ny511 provider switch and returns the DAA credit
  + NYSDOT as-is disclaimer; 511NY event descriptions no longer truncated
  ("may not alter the substance of a report").

Frontend:
- LiveView becomes the ops wall: Region > Incident > Camera drill-down,
  worst-first rail (MapView), KPIs, transcript ticker, scrubber incident
  bands, auto-tour, deep links (#inc=&cam=&tour), Esc steps up.
- Incident panel: nearest cameras (path-weighted), fused situational context
  (ADS-B, AIS, 511NY events, NEXRAD tile sample), units, call spine.
- MapView keeps every layer; adds Camera Viewsheds (approx.) overlay and a
  nearest-camera layer for the selected incident.
- CameraFeed hygiene: hidden-tab/off-screen gating, 2 concurrent HLS cap,
  last good frame + stale badge, frozen-frame signature, HLS stall watchdog,
  provider attribution rendered on the imagery.
- Camera/event popups show source credit, update time and the disclaimer.
- Admin > Camera providers tab with licence status, health, gated confirm.
- Camera detection is not built (blocked on #199/#200); seam only.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

drb-frontend/lib/c2api.ts

@@ -1,5 +1,5 @@
 import { auth } from "@/lib/firebase";
-import type { AreaContext, Ny511Response, TalkgroupPending } from "@/lib/types";
+import type { AreaContext, CameraProviderAdmin, CamerasResponse, Ny511Response, TalkgroupPending } from "@/lib/types";
 
 const BASE = process.env.NEXT_PUBLIC_C2_URL ?? "http://localhost:8000";
 
@@ -390,6 +390,21 @@ export const c2api = {
       south: String(bbox.south), west: String(bbox.west), north: String(bbox.north), east: String(bbox.east), layers,
     })}`),
 
+  // Public cameras from every admin-enabled provider inside a bbox (live ops wall)
+  getCameras: (bbox: { south: number; west: number; north: number; east: number }) =>
+    request<CamerasResponse>(`/cameras?${new URLSearchParams({
+      south: String(bbox.south), west: String(bbox.west), north: String(bbox.north), east: String(bbox.east),
+    })}`),
+
+  // Admin → Camera providers. A licence-gated provider answers 409 with
+  // `requires_acknowledgement` until `acknowledge_licence` is sent.
+  listCameraProviders: () => request<{ providers: CameraProviderAdmin[] }>("/admin/camera-providers"),
+  setCameraProvider: (id: string, enabled: boolean, acknowledgeLicence = false) =>
+    request<CameraProviderAdmin>(`/admin/camera-providers/${encodeURIComponent(id)}`, {
+      method: "PUT",
+      body: JSON.stringify({ enabled, acknowledge_licence: acknowledgeLicence }),
+    }),
+
   // Public waitlist — no auth, see routers/waitlist.py
   joinWaitlist: (body: { email: string; org_name?: string; note?: string }) =>
     request<{ ok: boolean }>("/waitlist", { method: "POST", body: JSON.stringify(body) }),