Don't show suggest widget when shell tab completion has occurred (#252305)

* Initial plan for issue

* Add tab key detection to prevent suggest widget after shell completion

Co-authored-by: meganrogge <29464607+meganrogge@users.noreply.github.com>

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: meganrogge <29464607+meganrogge@users.noreply.github.com>

Author: Copilot

src/vs/workbench/contrib/terminalContrib/suggest/browser/terminalSuggestAddon.ts

@@ -414,7 +414,7 @@ export class SuggestAddon extends Disposable implements ITerminalAddon, ISuggest
 	}
 
 	private _requestTriggerCharQuickSuggestCompletions(): boolean {
-		if (!this._wasLastInputVerticalArrowKey()) {
+		if (!this._wasLastInputVerticalArrowKey() && !this._wasLastInputTabKey()) {
 			// Only request on trigger character when it's a regular input, or on an arrow if the widget
 			// is already visible
 			if (!this._wasLastInputIncludedEscape() || this._terminalSuggestWidgetVisibleContextKey.get()) {
@@ -447,6 +447,10 @@ export class SuggestAddon extends Disposable implements ITerminalAddon, ISuggest
 		return !!this._lastUserData?.match(/^\x1b[\[O]?[A-D]$/);
 	}
 
+	private _wasLastInputTabKey(): boolean {
+		return this._lastUserData === '\t';
+	}
+
 	private _sync(promptInputState: IPromptInputModelState): void {
 		const config = this._configurationService.getValue<ITerminalSuggestConfiguration>(terminalSuggestConfigSection);
 		{