fix(tui): expand paste markers when opening external editor (#444)

* fix(tui): expand paste markers when opening external editor

Add getExpandedText() method to Editor that substitutes paste markers
with actual content. Use it in Ctrl-G external editor flow so users
see full pasted content instead of [paste #N ...] placeholders.

* docs: add changelog entries for #444

packages/tui/CHANGELOG.md

@@ -2,6 +2,10 @@
 
 ## [Unreleased]
 
+### Added
+
+- `Editor.getExpandedText()` method that returns text with paste markers expanded to their actual content ([#444](https://github.com/badlogic/pi-mono/pull/444) by [@aliou](https://github.com/aliou))
+
 ## [0.33.0] - 2026-01-04
 
 ### Breaking Changes

packages/tui/src/components/editor.ts

@@ -696,6 +696,19 @@ export class Editor implements Component {
 		return this.state.lines.join("\n");
 	}
 
+	/**
+	 * Get text with paste markers expanded to their actual content.
+	 * Use this when you need the full content (e.g., for external editor).
+	 */
+	getExpandedText(): string {
+		let result = this.state.lines.join("\n");
+		for (const [pasteId, pasteContent] of this.pastes) {
+			const markerRegex = new RegExp(`\\[paste #${pasteId}( (\\+\\d+ lines|\\d+ chars))?\\]`, "g");
+			result = result.replace(markerRegex, pasteContent);
+		}
+		return result;
+	}
+
 	getLines(): string[] {
 		return [...this.state.lines];
 	}