feat(tui): support autocomplete trigger characters

closes #4703

packages/coding-agent/src/modes/interactive/interactive-mode.ts

@@ -555,8 +555,13 @@ export class InteractiveMode {
 
 	private setupAutocompleteProvider(): void {
 		let provider = this.createBaseAutocompleteProvider();
+		const triggerCharacters: string[] = [];
 		for (const wrapProvider of this.autocompleteProviderWrappers) {
 			provider = wrapProvider(provider);
+			triggerCharacters.push(...(provider.triggerCharacters ?? []));
+		}
+		if (triggerCharacters.length > 0) {
+			provider.triggerCharacters = [...new Set(triggerCharacters)];
 		}
 
 		this.autocompleteProvider = provider;