feat(ui): adopt canonical WS session key format + channel filter

- buildNewSessionKey uses agent:{id}:ws:direct:{uuid} format
- sessions.list sends channel:"ws" to filter WS-only sessions
- isOwnSession supports both new and legacy key formats
- Read-only bar now floating with rounded corners

ui/web/src/lib/session-key.ts

@@ -21,11 +21,13 @@ export function buildSessionKey(agentId: string, scope: string): string {
 
 /**
  * Check if a session belongs to the current web user.
- * Web sessions have scope format: "ws-{userId}-{timestamp}".
+ * New format: "ws:direct:{convId}" — API already filters by userId, so all WS sessions are own.
+ * Legacy format: "ws-{userId}-{timestamp}".
  * Sessions from other channels (telegram, discord, etc.) are foreign.
  */
 export function isOwnSession(sessionKey: string, userId: string): boolean {
   if (!userId) return false;
   const { scope } = parseSessionKey(sessionKey);
+  if (scope.startsWith("ws:direct:")) return true;
   return scope.startsWith(`ws-${userId}-`);
 }

ui/web/src/pages/chat/chat-page.tsx

@@ -108,11 +108,11 @@ export function ChatPage() {
   const handleAgentChange = useCallback(
     (newAgentId: string) => {
       setAgentId(newAgentId);
-      const newKey = `agent:${newAgentId}:ws-${userId}-${Date.now().toString(36)}`;
+      const newKey = `agent:${newAgentId}:ws:direct:${crypto.randomUUID()}`;
       setSessionKey(newKey);
       navigate(`/chat/${encodeURIComponent(newKey)}`);
     },
-    [navigate, userId],
+    [navigate],
   );
 
   const handleSend = useCallback(
@@ -235,7 +235,7 @@ export function ChatPage() {
               disabled={!connected}
             />
           ) : (
-            <div className="flex items-center gap-2 border-t bg-muted/50 px-4 py-3 text-sm text-muted-foreground">
+            <div className="mx-3 mb-3 flex items-center gap-2 rounded-xl border bg-muted/50 px-4 py-3 text-sm text-muted-foreground shadow-sm">
               <Eye className="h-4 w-4" />
               {t("readOnly")}
             </div>

ui/web/src/pages/chat/hooks/use-chat-sessions.ts

@@ -10,7 +10,6 @@ import { useAuthStore } from "@/stores/use-auth-store";
  */
 export function useChatSessions(agentId: string) {
   const ws = useWs();
-  const userId = useAuthStore((s) => s.userId);
   const connected = useAuthStore((s) => s.connected);
   const [sessions, setSessions] = useState<SessionInfo[]>([]);
   const [loading, setLoading] = useState(true);
@@ -23,7 +22,7 @@ export function useChatSessions(agentId: string) {
     try {
       const res = await ws.call<{ sessions: SessionInfo[] }>(
         Methods.SESSIONS_LIST,
-        { agentId },
+        { agentId, channel: "ws" },
       );
       const sorted = (res.sessions ?? []).sort(
         (a: SessionInfo, b: SessionInfo) =>
@@ -42,9 +41,9 @@ export function useChatSessions(agentId: string) {
   }, [loadSessions]);
 
   const buildNewSessionKey = useCallback(() => {
-    const ts = Date.now().toString(36);
-    return `agent:${agentId}:ws-${userId}-${ts}`;
-  }, [agentId, userId]);
+    const convId = crypto.randomUUID();
+    return `agent:${agentId}:ws:direct:${convId}`;
+  }, [agentId]);
 
   return {
     sessions,