feat: read teams_bridge_endpoint from status instead of deriving it

Add optional OUTPUT_ONLY teams_bridge_endpoint field to AIAgent.
The bridge controller populates this when it starts serving, so
console just displays it -- no URL gymnastics needed.

Author: birdayz

backend/pkg/protogen/redpanda/api/dataplane/v1alpha3/ai_agent.pb.go

@@ -57,22 +57,6 @@ const extractSecretName = (ref: string): string => {
   return match ? match[1] : '';
 };
 
-// Agent URL format: https://<agent-id>.ai-agents.<cluster>.clusters.ign.rdpa.co
-const getMessagingEndpointUrl = (agentUrl: string, agentId: string): string => {
-  try {
-    const url = new URL(agentUrl);
-    const hostParts = url.hostname.split('.');
-    const aiAgentsIndex = hostParts.indexOf('ai-agents');
-    if (aiAgentsIndex < 0 || aiAgentsIndex + 1 >= hostParts.length) {
-      return '';
-    }
-    const clusterDomain = hostParts.slice(aiAgentsIndex + 1).join('.');
-    return `https://msteams-bridge.${clusterDomain}/msteams/v1/${agentId}`;
-  } catch {
-    return '';
-  }
-};
-
 // biome-ignore lint/complexity/noExcessiveCognitiveComplexity: Integrations tab with edit/view mode conditionals
 export const AIAgentIntegrationsTab = () => {
   const { id } = routeApi.useParams();
@@ -158,8 +142,6 @@ export const AIAgentIntegrationsTab = () => {
     setEditedState(null);
   };
 
-  const messagingEndpointUrl = agent.teamsBridge?.enabled && agent.url ? getMessagingEndpointUrl(agent.url, id) : '';
-
   return (
     <div className="space-y-4">
       <Card className="px-0 py-0" size="full">
@@ -265,14 +247,14 @@ export const AIAgentIntegrationsTab = () => {
             )}
           </div>
 
-          {/* Messaging endpoint URL - shown when integration is saved and enabled */}
-          {Boolean(agent.teamsBridge?.enabled && messagingEndpointUrl) && (
+          {/* Messaging endpoint URL - populated by the bridge controller */}
+          {Boolean(agent.teamsBridgeEndpoint) && (
             <div className="space-y-2">
               <Label>Messaging Endpoint</Label>
               <Text className="text-muted-foreground text-sm">
                 Configure this URL as the messaging endpoint in your Azure Bot registration.
               </Text>
-              <DynamicCodeBlock code={messagingEndpointUrl} lang="text" />
+              <DynamicCodeBlock code={agent.teamsBridgeEndpoint ?? ''} lang="text" />
             </div>
           )}
         </CardContent>

frontend/src/components/pages/agents/details/ai-agent-integrations-tab.tsx

@@ -54,6 +54,11 @@ components:
           type: object
         teams_bridge:
           $ref: '#/components/schemas/AIAgentTeamsBridge'
+        teams_bridge_endpoint:
+          description: Messaging endpoint URL for the Teams bridge, populated by the bridge controller.
+          nullable: true
+          readOnly: true
+          type: string
         url:
           description: URL to connect to the AI agent endpoint.
           readOnly: true

frontend/src/protogen/redpanda/api/dataplane/v1alpha3/ai_agent_pb.ts

@@ -111,6 +111,9 @@ message AIAgent {
   // Optional Microsoft Teams bridge configuration.
   AIAgentTeamsBridge teams_bridge = 18;
 
+  // Messaging endpoint URL for the Teams bridge, populated by the bridge controller.
+  optional string teams_bridge_endpoint = 19 [(google.api.field_behavior) = OUTPUT_ONLY];
+
   message Provider {
     message OpenAI {
       string api_key = 1 [