fix(tui): voice TTS speak-back + transcript-key bug + auto-submit

Three issues surfaced during end-to-end testing of the CLI-parity voice
loop and are fixed together because they all blocked "speak → agent
responds → TTS reads it back" from working at all:

1. Wrong result key (hermes_cli/voice.py)

   transcribe_recording() returns {"success": bool, "transcript": str},
   matching cli.py:_voice_stop_and_transcribe. The wrapper was reading
   result.get("text"), which is None, so every successful Groq / local
   STT response was thrown away and the 3-strikes halt fired after
   three silent-looking cycles. Fixed by reading "transcript" and also
   honouring "success" like the CLI does. Updated the loop simulation
   tests to return the correct shape.

2. TTS speak-back was missing (tui_gateway/server.py + hermes_cli/voice.py)

   The TUI had a voice.toggle "tts" subcommand but nothing downstream
   actually read the flag — agent replies never spoke. Mirrored
   cli.py:8747-8754's dispatch: on message.complete with status ==
   "complete", if _voice_tts_enabled() is true, spawn a daemon thread
   running speak_text(response). Rewrote speak_text as a full port of
   cli.py:_voice_speak_response — same markdown-strip regex pipeline
   (code blocks, links, bold/italic, inline code, headers, list bullets,
   horizontal rules, excessive newlines), same 4000-char cap, same
   explicit mp3 output path, same MP3-over-OGG playback choice (afplay
   misbehaves on OGG), same cleanup of both extensions. Keeps TUI TTS
   audible output byte-for-byte identical to the classic CLI.

3. Auto-submit swallowed on non-empty composer (createGatewayEventHandler.ts)

   The voice.transcript handler branched on prev input via a setInput
   updater and fired submitRef.current inside the updater when prev was
   empty. React strict mode double-invokes state updaters, which would
   queue the submit twice; and when the composer had any content the
   transcript was merely appended — the agent never saw it. CLI
   _pending_input.put(transcript) unconditionally feeds the transcript
   as the next turn, so match that: always clear the composer and
   setTimeout(() => submitRef.current(text), 0) outside any updater.
   Side effect can't run twice this way, and a half-typed draft on the
   rare occasion is a fair trade vs. silently dropping the turn.

Also added peak_rms to the rec.stop debug line so "recording too quiet"
is diagnosable at a glance when HERMES_VOICE_DEBUG=1.

tui_gateway/server.py

@@ -2126,6 +2126,28 @@ def _(rid, params: dict) -> dict:
             if rendered:
                 payload["rendered"] = rendered
             _emit("message.complete", sid, payload)
+
+            # CLI parity: when voice-mode TTS is on, speak the agent reply
+            # (cli.py:_voice_speak_response).  Only the final text — tool
+            # calls / reasoning already stream separately and would be
+            # noisy to read aloud.
+            if (
+                status == "complete"
+                and isinstance(raw, str)
+                and raw.strip()
+                and _voice_tts_enabled()
+            ):
+                try:
+                    from hermes_cli.voice import speak_text
+
+                    spoken = raw
+                    threading.Thread(
+                        target=speak_text, args=(spoken,), daemon=True
+                    ).start()
+                except ImportError:
+                    logger.warning("voice TTS skipped: hermes_cli.voice unavailable")
+                except Exception as e:
+                    logger.warning("voice TTS dispatch failed: %s", e)
         except Exception as e:
             _emit("error", sid, {"message": str(e)})
         finally: