feat: US-009 - Autocomplete voci din catalog pentru /audio și /voice setvoice

- tools/tts.py: +list_voice_names(engine=None), sursă live din tts_voices.json
- src/fast_commands.py: _VOICES statice -> _supertonic_voice_names() din catalog
- discord_bot.py /audio și discord_voice.py /voice setvoice: choices statice -> autocomplete live
- gates rulate: tests PASS (1043 passed, 22 eșecuri preexistente neschimbate), ui/backend review PASS manual

src/adapters/discord_voice.py

@@ -140,6 +140,19 @@ def _parse_registered_voice_name(stdout: str) -> Optional[str]:
     return m.group(1) if m else None
 
 
+def _tts_voice_names() -> list[str]:
+    """Nume de voci din tts_voices.json (import lazy din tools/tts.py, catalog live)."""
+    import sys as _sys
+    tools_dir = str(PROJECT_ROOT / "tools")
+    if tools_dir not in _sys.path:
+        _sys.path.insert(0, tools_dir)
+    try:
+        import tts as _tts_mod
+        return _tts_mod.list_voice_names()
+    except Exception:
+        return []
+
+
 def _tts_synthesize_preview(text: str, voice: str) -> dict:
     """Import tools/tts.py (nu e package, sys.path trick) și generează un preview audio."""
     import sys as _sys
@@ -301,20 +314,27 @@ def register(tree: app_commands.CommandTree, bot: discord.Client) -> app_command
             log.warning("Presence reset skipped", exc_info=True)
         await interaction.followup.send("Plecat.", ephemeral=True)
 
-    _VOICE_CHOICES = [
-        app_commands.Choice(name=v, value=v)
-        for v in ("M1", "M2", "M3", "M4", "M5", "F1", "F2", "F3", "F4", "F5")
-    ]
+    async def _voice_autocomplete(
+        interaction: discord.Interaction, current: str
+    ) -> list[app_commands.Choice[str]]:
+        current_low = (current or "").lower()
+        names = [n for n in _tts_voice_names() if current_low in n.lower()]
+        return [app_commands.Choice(name=n, value=n) for n in names[:25]]
 
-    @voice_group.command(name="setvoice", description="Schimbă vocea Echo (M1-M5 sau F1-F5)")
+    @voice_group.command(name="setvoice", description="Schimbă vocea Echo (din catalogul tts_voices.json)")
     @app_commands.describe(voice="Voce nouă")
-    @app_commands.choices(voice=_VOICE_CHOICES)
+    @app_commands.autocomplete(voice=_voice_autocomplete)
     async def setvoice(
         interaction: discord.Interaction,
-        voice: app_commands.Choice[str],
+        voice: str,
     ) -> None:
         await interaction.response.defer(ephemeral=True)
-        new_voice = voice.value
+        if voice not in _tts_voice_names():
+            await interaction.followup.send(
+                f"Voce necunoscută: {voice!r}. Alege din autocomplete.", ephemeral=True
+            )
+            return
+        new_voice = voice
         # Live-swap on the active session if Echo is in voice on this guild.
         guild_id = interaction.guild.id if interaction.guild else None
         session = _voice_sessions.get(guild_id) if guild_id is not None else None