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/components/text.ts

@@ -37,8 +37,9 @@ export class Text implements Component {
 		// Calculate available width for content (subtract horizontal padding)
 		const contentWidth = Math.max(1, width - this.paddingX * 2);
 
-		if (!this.text) {
-			const result = [""];
+		// Don't render anything if there's no actual text
+		if (!this.text || this.text.trim() === "") {
+			const result: string[] = [];
 			// Update cache
 			this.cachedText = this.text;
 			this.cachedWidth = width;