Add /thinking command and improve TUI UX

- Add /thinking slash command with autocomplete for setting reasoning levels (off, minimal, low, medium, high)
- Fix Ctrl+C behavior: remove hardcoded exit in TUI, let focused component handle it
- Add empty lines before and after tool execution components for better visual separation
- Fix stats rendering: display stats AFTER tool executions complete (matches web-ui behavior)
- Remove "Press Ctrl+C again to exit" message, show "(esc to interrupt)" in loader instead
- Add bash tool abort signal support with immediate SIGKILL on interrupt
- Make Text and Markdown components return empty arrays when no actual text content
- Add setCustomBgRgb() method to Markdown for dynamic background colors

packages/tui/src/tui.ts

@@ -98,13 +98,8 @@ export class TUI extends Container {
 	}
 
 	private handleInput(data: string): void {
-		// Exit on Ctrl+C
-		if (data === "\x03") {
-			this.stop();
-			process.exit(0);
-		}
-
-		// Pass input to focused component
+		// Pass input to focused component (including Ctrl+C)
+		// The focused component can decide how to handle Ctrl+C
 		if (this.focusedComponent?.handleInput) {
 			this.focusedComponent.handleInput(data);
 			this.requestRender();