fix(gui): Resolve AttributeError in imscope.indent and stabilize render loop

- Add 'indent' context manager to src/imgui_scopes.py.
- Refactor manual imgui.indent/unindent calls in src/gui_2.py to use imscope.indent.
- Fix cascading ImGui assertion failures caused by Open/Close mismatches during exceptions.
- Finalize 'Selectable Thinking Monologs' track.

conductor/tracks.md

@@ -278,5 +278,5 @@ This file tracks all major tracks for the project. Each track has its own detail
 
 ---
 
-- [~] **Track: Selectable Thinking Monologs**
+- [x] **Track: Selectable Thinking Monologs**
 *Link: [./tracks/selectable_thinking_monologs_20260601/](./tracks/selectable_thinking_monologs_20260601/)*

conductor/tracks/selectable_thinking_monologs_20260601/plan.md

@@ -11,8 +11,8 @@
     - [x] If `thinking_read_mode` is `False` (Pure mode), use `render_selectable_label(app, f"think_text_...", content, multiline=True, height=-1)` to make the text selectable and copyable.
 
 ## Phase 2: Verification
-- [ ] Task: Verification
-    - [ ] Verify that thinking traces in the Discussion Hub can be toggled between Pure and Read modes.
-    - [ ] Verify that text can be selected and copied via Ctrl+C in Pure mode.
-    - [ ] Verify that the change does not crash other areas rendering thinking traces (like Comms History).
-- [ ] Task: Conductor - User Manual Verification 'Phase 2: Verification' (Protocol in workflow.md)
+- [x] Task: Verification
+    - [x] Verify that thinking traces in the Discussion Hub can be toggled between Pure and Read modes.
+    - [x] Verify that text can be selected and copied via Ctrl+C in Pure mode.
+    - [x] Verify that the change does not crash other areas rendering thinking traces (like Comms History).
+- [x] Task: Conductor - User Manual Verification 'Phase 2: Verification' (Protocol in workflow.md)