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/agent/test_loop_progress.py

@@ -651,7 +651,7 @@ class TestToolEventProgress:
             return False
 
         monkeypatch.setattr(
-            "nanobot.utils.webui_turn_helpers.maybe_generate_webui_title_after_turn",
+            "nanobot.session.webui_turns.maybe_generate_webui_title_after_turn",
             fake_title_after_turn,
         )
         scheduled_title: list[object] = []
@@ -698,7 +698,7 @@ class TestToolEventProgress:
             raise AssertionError("command-only turns should not generate titles")
 
         monkeypatch.setattr(
-            "nanobot.utils.webui_turn_helpers.maybe_generate_webui_title_after_turn",
+            "nanobot.session.webui_turns.maybe_generate_webui_title_after_turn",
             fake_title_after_turn,
         )
         scheduled: list[object] = []