feat(stt-log): log the WHOLE turn pipeline to the transcript channel

The transcript channel only showed successful transcripts, so dropped utterances
(the 47/50 misses) were invisible. Now every captured utterance is mirrored with
its outcome and per-stage timing:
- too-short blip (<300ms), VAD "음성 아님(VAD 차단)", "인식 실패", "답변 없음", or "ok"
- transcript + reply (or "(무응답)")
- ⏱️ stt/llm seconds

The bridge meta now carries note + stt_sec + think_sec; voice.ts fires onTurn for
every turn (not only non-empty transcripts) and for the too-short drop; userbot
formats the diagnostic line.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

bot/src/userbot.ts

@@ -34,16 +34,33 @@ async function loadSelfbot(): Promise<any> {
   }
 }
 
-/** Mirror a heard voice turn (transcript + reply) into a text channel. */
-async function postTranscript(client: AnyClient, transcript: string, reply: string): Promise<void> {
+interface TurnInfo {
+  transcript: string;
+  reply: string;
+  note?: string;
+  sttSec?: number;
+  thinkSec?: number;
+}
+
+/** Mirror EVERY heard utterance (and why it did/didn't answer) to a text
+ *  channel, so misses and latency are diagnosable without hearing the bot. */
+async function postTranscript(client: AnyClient, info: TurnInfo): Promise<void> {
   const chId = config.transcriptChannelId;
   if (!chId) return;
+  const timing =
+    info.sttSec != null || info.thinkSec != null
+      ? `  ⏱️ stt ${info.sttSec ?? "?"}s · llm ${info.thinkSec ?? "?"}s`
+      : "";
+  let msg: string;
+  if (info.transcript) {
+    const r = (info.reply || "").trim();
+    msg = `🎤 들음 → 🗣️ "${info.transcript}"\n🤖 답변: ${r || "(무응답)"}${timing}`;
+  } else {
+    msg = `🎤 들음 → ❌ ${info.note || "무시됨"}${timing}`;
+  }
   try {
     const ch: any = await client.channels.fetch(chId).catch(() => null);
-    if (ch?.send) {
-      const r = (reply || "").trim();
-      await ch.send(`🗣️ 들은 말: ${transcript}\n🤖 답변: ${r || "(무응답)"}`);
-    }
+    if (ch?.send) await ch.send(msg);
   } catch (e) {
     console.error("[userbot] transcript post failed:", e);
   }
@@ -58,11 +75,11 @@ async function joinAndListen(client: AnyClient, channelId: string): Promise<void
   // The selfbot VoiceChannel is runtime-compatible with @discordjs/voice's
   // joinVoiceChannel (it exposes id, guild.id and guild.voiceAdapterCreator).
   const session = await joinChannel(channel as unknown as VoiceBasedChannel);
-  session.onTurn = ({ transcript, reply }) => {
-    console.log(`🗣️  ${transcript}\n🤖 ${reply}`);
-    // Mirror every heard utterance (and the reply, if any) to a text channel so
-    // you can see what the bot understood even when it doesn't answer aloud.
-    void postTranscript(client, transcript, reply);
+  session.onTurn = (info) => {
+    console.log(`🗣️  ${info.transcript || "(" + (info.note || "empty") + ")"}\n🤖 ${info.reply}`);
+    // Mirror every heard utterance (and the reply / drop reason) to a text
+    // channel so you can see what the bot understood even when it doesn't answer.
+    void postTranscript(client, info);
   };
   // Screen-share mode (STREAM_BROWSER=true): auto-start the broadcast on join,
   // report its live state to the brain each turn, and let the brain toggle it by