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.

ui-tui/src/app/createGatewayEventHandler.ts

@@ -301,19 +301,16 @@ export function createGatewayEventHandler(ctx: GatewayEventHandlerContext): (ev:
           return
         }
 
-        // Match CLI's _pending_input.put(transcript): auto-submit when the
-        // composer is empty, otherwise append so the user can keep editing
-        // a partial draft they were working on.
-        setInput(prev => {
-          if (!prev) {
-            // defer submit so React commits the state change first
-            setTimeout(() => submitRef.current(text), 0)
-
-            return ''
-          }
-
-          return `${prev}${/\s$/.test(prev) ? '' : ' '}${text}`
-        })
+        // CLI parity: _pending_input.put(transcript) unconditionally feeds
+        // the transcript to the agent as its next turn — draft handling
+        // doesn't apply because voice-mode users are speaking, not typing.
+        //
+        // We can't branch on composer input from inside a setInput updater
+        // (React strict mode double-invokes it, duplicating the submit).
+        // Just clear + defer submit so the cleared input is committed before
+        // submit reads it.
+        setInput('')
+        setTimeout(() => submitRef.current(text), 0)
 
         return
       }