saving status before scene frame fix after rust change

cht/window.py

@@ -46,6 +46,7 @@ class ChtWindow(Adw.ApplicationWindow):
         self._pending_scrub_global = 0.0
         self._scrub_pending = False  # throttle flag for scrub updates
         self._telemetry = None
+        self._threshold_timeout_id = None
 
         # Core components
         self._timeline = Timeline()
@@ -161,11 +162,23 @@ class ChtWindow(Adw.ApplicationWindow):
             )
 
     def _on_scene_threshold(self, val):
-        if self._lifecycle.stream_mgr and not self._lifecycle.stream_mgr.readonly:
-            old = self._lifecycle.stream_mgr.scene_threshold
-            self._lifecycle.stream_mgr.update_scene_threshold(val)
-            if self._telemetry:
-                self._telemetry.event("scene_threshold_changed", {"from": old, "to": val})
+        if not (self._lifecycle.stream_mgr and not self._lifecycle.stream_mgr.readonly):
+            return
+        if self._telemetry:
+            self._telemetry.event("scene_threshold_changed",
+                                  {"from": self._lifecycle.stream_mgr.scene_threshold, "to": val})
+        # Debounce: wait 500ms after user stops dragging, then restart in background.
+        if self._threshold_timeout_id:
+            GLib.source_remove(self._threshold_timeout_id)
+        self._threshold_timeout_id = GLib.timeout_add(500, self._apply_threshold, val)
+
+    def _apply_threshold(self, val):
+        self._threshold_timeout_id = None
+        mgr = self._lifecycle.stream_mgr
+        if mgr and not mgr.readonly:
+            Thread(target=mgr.update_scene_threshold, args=(val,),
+                   daemon=True, name="threshold_update").start()
+        return False  # don't repeat
 
     def _on_min_chunk_changed(self, panel, val):
         import cht.config
@@ -247,6 +260,9 @@ class ChtWindow(Adw.ApplicationWindow):
         self._update_scrub_bar_manifest()
         self._populate_model_dropdown()
 
+        # Show "Continue" since there's an active session to resume
+        self._connect_btn.set_label("Continue")
+
         # Load persisted agent conversation
         self._agent.load_from_session(mgr.session_dir)
         if self._agent.thread.messages:
@@ -263,8 +279,11 @@ class ChtWindow(Adw.ApplicationWindow):
             audio_dir = mgr.audio_dir
             audio_dir.mkdir(parents=True, exist_ok=True)
             full_wav = audio_dir / "full.wav"
+            # Rust transport writes audio to a separate file (fMP4 has no audio track).
+            aac_path = mgr.stream_dir / "audio.aac"
+            source = aac_path if aac_path.exists() else segments[0]
             try:
-                ff.extract_audio_chunk(segments[0], full_wav)
+                ff.extract_audio_chunk(source, full_wav)
                 self._waveform_engine.compute_full(full_wav)
                 peaks = self._waveform_engine.peaks
                 bucket_dur = self._waveform_engine.bucket_duration
@@ -483,8 +502,18 @@ class ChtWindow(Adw.ApplicationWindow):
         if self._proxy_mgr:
             self._proxy_mgr.cancel()
             self._proxy_mgr = None
-        self._manifest = []
 
+        self._connect_btn.set_label("Connect")
+        self._connect_btn.remove_css_class("destructive-action")
+        self._connect_btn.add_css_class("suggested-action")
+
+        if reload_session and last_session_id:
+            # Transition to review mode — _load_session handles UI setup
+            self._load_session(last_session_id)
+            return
+
+        # Full reset — only when not reloading
+        self._manifest = []
         self._timeline.reset()
         self._timeline_controls.scrub_bar.set_manifest([])
         self._monitor.reset()
@@ -493,18 +522,10 @@ class ChtWindow(Adw.ApplicationWindow):
         self._transcriber.reset()
         self._agent.clear_history()
         self._known_frames = set()
-
         self._frames_panel.clear()
         self._transcript_panel.clear()
-
-        self._connect_btn.set_label("Connect")
-        self._connect_btn.remove_css_class("destructive-action")
-        self._connect_btn.add_css_class("suggested-action")
         self.set_title(APP_NAME)
 
-        if reload_session and last_session_id:
-            GLib.idle_add(self._load_session, last_session_id)
-
     def _on_close(self, *args):
         self.teardown()