feat(discord): add /audio slash command with voce + text_sau_url params

Adds missing /audio slash command on Discord with:
- voce: optional choices M1-M5 / F1-F5 with descriptions
- text_sau_url: optional text or URL input
- handles __AUDIO__: response by sending WAV as file attachment

Telegram already had /audio fully implemented.

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

src/adapters/discord_bot.py

@@ -909,6 +909,51 @@ def create_bot(config: Config) -> discord.Client:
                 f"Error reading logs: {e}", ephemeral=True
             )
 
+    @tree.command(name="audio", description="TTS: convertește text sau URL în voice note")
+    @app_commands.describe(
+        voce="Voce (M1-M5 masculin, F1-F5 feminin; default M2)",
+        text_sau_url="Text direct, URL articol, sau gol pentru ultimul răspuns Echo",
+    )
+    @app_commands.choices(
+        voce=[
+            app_commands.Choice(name="M1 — Masculin 1", value="M1"),
+            app_commands.Choice(name="M2 — Masculin 2 (default)", value="M2"),
+            app_commands.Choice(name="M3 — Masculin 3", value="M3"),
+            app_commands.Choice(name="M4 — Masculin 4", value="M4"),
+            app_commands.Choice(name="M5 — Masculin 5", value="M5"),
+            app_commands.Choice(name="F1 — Feminin 1", value="F1"),
+            app_commands.Choice(name="F2 — Feminin 2", value="F2"),
+            app_commands.Choice(name="F3 — Feminin 3", value="F3"),
+            app_commands.Choice(name="F4 — Feminin 4", value="F4"),
+            app_commands.Choice(name="F5 — Feminin 5", value="F5"),
+        ]
+    )
+    async def audio_cmd(
+        interaction: discord.Interaction,
+        voce: str | None = None,
+        text_sau_url: str | None = None,
+    ) -> None:
+        await interaction.response.defer()
+        args: list[str] = []
+        if voce:
+            args.append(voce)
+        if text_sau_url:
+            args.extend(text_sau_url.split())
+        result = await asyncio.to_thread(fast_dispatch, "audio", args)
+        if result and result.startswith("__AUDIO__:"):
+            wav_path = result[len("__AUDIO__:"):]
+            try:
+                await interaction.followup.send(
+                    file=discord.File(wav_path, filename="echo-audio.wav")
+                )
+            finally:
+                try:
+                    os.unlink(wav_path)
+                except OSError:
+                    pass
+        else:
+            await interaction.followup.send(result or "Eroare TTS.")
+
     # --- Ralph commands (autonomous project execution) ---
 
     async def _autocomplete_by_status(