unify k8s naming: drop be/fe split, single switchboard deployment

- k8s/backend.yaml → k8s/switchboard.yaml (already renamed)
- Deployment/Service name: switchboard-be → switchboard
- Removed component:backend labels (single image, no component split)
- Ingress: all paths route to switchboard service on :8080
- CI: updated manifest render, apply, and rollout references
- Removed stale extractor sidecar and extraction env vars
- Updated CHANGELOG and ROADMAP with CI fixes and design decisions

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

k8s/ingress.yaml

@@ -13,7 +13,7 @@
 #
 # BASE_PATH is empty for prod, "/test" or "/dev" for others.
 # Backend handles BASE_PATH via r.Group(cfg.BasePath).
-# Frontend entrypoint injects BASE_PATH into nginx + HTML.
+# Single unified image serves both API and static assets.
 # ============================================
 apiVersion: networking.k8s.io/v1
 kind: Ingress
@@ -36,36 +36,11 @@ spec:
   - host: "${DEPLOY_HOST}"
     http:
       paths:
-      # API routes → backend
-      - path: ${BASE_PATH}/api
-        pathType: Prefix
-        backend:
-          service:
-            name: switchboard-be${DEPLOY_SUFFIX}
-            port:
-              number: 8080
-      # Health check → backend
-      - path: ${BASE_PATH}/health
-        pathType: Prefix
-        backend:
-          service:
-            name: switchboard-be${DEPLOY_SUFFIX}
-            port:
-              number: 8080
-      # WebSocket → backend (must be Prefix, not Exact — Traefik's Exact
-      # doesn't reliably win over Prefix rules in the same Ingress resource)
-      - path: ${BASE_PATH}/ws
-        pathType: Prefix
-        backend:
-          service:
-            name: switchboard-be${DEPLOY_SUFFIX}
-            port:
-              number: 8080
-      # Everything else under this prefix → frontend
+      # All traffic → switchboard (unified image)
       - path: ${BASE_PATH}/
         pathType: Prefix
         backend:
           service:
-            name: switchboard-fe${DEPLOY_SUFFIX}
+            name: switchboard${DEPLOY_SUFFIX}
             port:
-              number: 80
+              number: 8080