wb/pm: pin KAFKA_TOPICS planning -> message-hub-prod (INFRA-3023)

pm on WB published to Kafka topic "pm" (stale .env mounted via subPath),
while message-hub consumes "message-hub-prod". PDF export of KSG hung in
PENDING because get_converted_file never reached message-hub.

Set KAFKA_TOPICS explicitly in backend and celery so env overrides .env,
same as prod, d8-ugmk-prod, uralkal and vad.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01173KBT2kTwhxrzr2t3KutB

apps/pm/wb/backend.yaml

@@ -147,6 +147,10 @@ spec:
             value:
               _default: "/api/v1"
 
+          - name: KAFKA_TOPICS
+            value:
+              _default: '{"planning": "message-hub-prod"}'
+
         commitSha: ""
         gitlabUri: ""
         gitlabJobUrl: ""

apps/pm/wb/celery.yaml

@@ -141,6 +141,10 @@ spec:
             value:
               _default: "/api/v1"
 
+          - name: KAFKA_TOPICS
+            value:
+              _default: '{"planning": "message-hub-prod"}'
+
         commitSha: ""
         gitlabUri: ""
         gitlabJobUrl: ""