feat(ctx): Fix Preview button sync and Text Viewer render loop

src/gui_2.py

@@ -1236,6 +1236,7 @@ def render_main_interface(app: App) -> None:
  app._render_window_if_open("Log Management",    lambda: render_log_management(app))
  app._render_window_if_open("Diagnostics",       lambda: render_diagnostics_panel(app))
  app._render_window_if_open("Context Preview",   lambda: render_context_preview_window(app))
+ app._render_window_if_open("Text Viewer",      lambda: render_text_viewer_window(app))
 
  app.perf_monitor.end_frame()
 
@@ -2837,7 +2838,11 @@ def render_context_batch_actions(app: App, total_lines: int, total_ast: int) ->
   app.ui_selected_context_files.clear()
  imgui.same_line()
  if imgui.button("Preview##ctx"):
-  app.context_preview_text = app.controller._do_generate()[0]
+  if not app.context_files:
+    app.context_preview_text = "# Context Composition Empty\n\nNo files have been added to the context composition yet."
+  else:
+    app.controller.context_files = app.context_files
+    app.context_preview_text = app.controller._do_generate()[0]
   app.show_windows["Context Preview"] = True
  imgui.same_line()
  imgui.text(f" | Total: {len(app.context_files)} files, {total_lines} lines, {total_ast} AST elements")
@@ -4193,6 +4198,7 @@ def render_text_viewer_window(app: App) -> None:
  #endregion: Inject File Modal
  
  render_ast_inspector_modal(app)
+ render_text_viewer_window(app)
  return
 
 def render_patch_modal(app: App) -> None: