Add chime endpoint to TTS server

POST /chime {name} plays chimes/<name>.wav or .ogg via pacat.
Goes through the same queue as speak so playback stays ordered.
chimes/ directory holds the audio files (not committed).

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

lib/tts-client.mjs

@@ -36,6 +36,18 @@ export class Tts_Client {
 		return res.json()   // { voices: [{name, description, active}], current }
 	}
 
+	async chime(name) {
+		const res = await fetch(`${this._url}/chime`, {
+			method:  'POST',
+			headers: { 'Content-Type': 'application/json' },
+			body:    JSON.stringify({ name }),
+		})
+		if (!res.ok) {
+			const data = await res.json().catch(() => ({}))
+			throw new Error(data.error ?? `HTTP ${res.status}`)
+		}
+	}
+
 	async set_voice(name) {
 		const res = await fetch(`${this._url}/voice`, {
 			method:  'POST',