fix: apply clang-format and exclude third-party libraries from formatting checks

- Applied clang-format to fix formatting violations in TUI and other source files
- Updated CMakeLists.txt to exclude src/lib/* from format targets to prevent third-party library violations
- Fixes clang-format violations in chat_tui.cc, tui.cc, and unified_layout.cc
- All source files now pass format-check target

🤖 Generated with Claude Code

Co-Authored-By: Claude <noreply@anthropic.com>

test/unit/gui/canvas_automation_api_test.cc

@@ -316,7 +316,8 @@ TEST_F(CanvasAutomationAPITest, CenterOn_ValidTile) {
   api_->CenterOn(0, 0);
   api_->CenterOn(20, 20);
 
-  // Verify scroll position changed (should be non-zero after centering on non-origin)
+  // Verify scroll position changed (should be non-zero after centering on
+  // non-origin)
   ImVec2 scroll = canvas_->scrolling();
   // Scroll values will depend on canvas size, just verify they're set
 }