feat(webui): upgrade settings and sidebar controls (#3906)

* feat(settings): expand settings api payload

* feat(webui): build app-style settings center

* feat(webui): add centered chat search dialog

* fix(webui): shorten chat search label

* fix(webui): center dialog entrance animation

* fix(webui): simplify chat search results

* fix(webui): tighten mobile settings navigation

* feat(webui): persist sidebar state

* feat(webui): add sidebar organization controls

* refactor(webui): organize backend helpers

* refactor(webui): remove utils compatibility shims

* refactor(session): move shared webui helpers out of webui package

* feat(webui): add image generation settings

* style(webui): refine settings overview layout

* fix(webui): localize settings zh-CN copy

* style(webui): add settings status indicators

* feat(webui): show sidebar run indicators

* fix(webui): persist sidebar run indicators

* fix(webui): highlight settings pending status

* fix(webui): align settings test with provider update

* fix(utils): preserve legacy webui helper imports

tests/utils/test_webui_transcript.py

@@ -2,7 +2,7 @@
 
 from __future__ import annotations
 
-from nanobot.utils.webui_transcript import (
+from nanobot.webui.transcript import (
     WEBUI_TRANSCRIPT_SCHEMA_VERSION,
     append_transcript_object,
     read_transcript_lines,
@@ -294,7 +294,7 @@ def test_replay_keeps_new_file_edit_after_reasoning_in_order(tmp_path, monkeypat
 
 
 def test_build_response_schema(monkeypatch, tmp_path) -> None:
-    from nanobot.utils.webui_transcript import build_webui_thread_response
+    from nanobot.webui.transcript import build_webui_thread_response
 
     monkeypatch.setattr("nanobot.config.paths.get_data_dir", lambda: tmp_path)
     key = "websocket:t3"