fix(ui): stream phase progress without gates

backend/src/bridge/session-bridge.ts

@@ -4,6 +4,15 @@ const GENERIC_MODEL_FAILURE =
   "Model request failed. Check provider connectivity, then Resume the session.";
 const SUBSCRIPTION_MODEL_FAILURE =
   "The selected model is unavailable for the current subscription. Choose another model and start a new session.";
+const PHASE_STARTED_NOTIFICATION_PREFIX = "__tht_phase_started__:";
+
+function phaseStartedNotification(message: unknown): string | null {
+  if (typeof message !== "string" || !message.startsWith(PHASE_STARTED_NOTIFICATION_PREFIX)) {
+    return null;
+  }
+  const phase = message.slice(PHASE_STARTED_NOTIFICATION_PREFIX.length);
+  return /^F[1-8]$/.test(phase) ? phase : "";
+}
 
 function safeModelFailure(error: unknown): string {
   const detail = typeof error === "string" ? error : "";
@@ -36,7 +45,7 @@ export type ClientEvent =
   | { type: "activity_event"; activity: ToolActivity }
   | { type: "usage"; usage: TokenUsage }
   | { type: "info"; [k: string]: any }
-  | { type: "system_event"; event: string };
+  | { type: "system_event"; event: string; phase?: string };
 
 export type TurnState = "idle" | "running" | "waiting" | "failed";
 
@@ -71,7 +80,11 @@ export class SessionBridge {
           });
         }
       } else if (m.type === "extension_ui_request" && m.method === "notify") {
-        this.fan({ type: "info", level: m.notifyType ?? "info", text: m.message ?? "" });
+        const phase = phaseStartedNotification(m.message);
+        if (phase) this.fan({ type: "system_event", event: "phase_started", phase });
+        else if (phase === null) {
+          this.fan({ type: "info", level: m.notifyType ?? "info", text: m.message ?? "" });
+        }
       } else if (m.type === "message_update" && m.assistantMessageEvent?.type === "text_delta") {
         this.fan({ type: "text_delta", text: m.assistantMessageEvent.delta ?? "" });
       } else if (m.type === "message_update" && m.assistantMessageEvent?.type === "thinking_delta") {