Node page Discord picker: org's linked servers + voice channels, not raw IDs (#213 item 3, #109 item 13)

- c2-core routers/discord_web.py:
  PUT  /discord/guilds/{id}/directory (service key): the server bot pushes each
       server's name + voice channels; merged onto discord_guilds, never touches org_id.
  GET  /discord/nodes/{id}/join-options: the node org's servers (same
       resolve rule as the bot), their voice channels with any live stream,
       radio-bot readiness + invite links, and this node's streams. No tokens.
  POST /discord/nodes/{id}/streams: stream pinned to the node; server must be
       the node org's, channel must be in the bot's directory, guild + node caps.
  POST /discord/nodes/{id}/streams/stop: one stream on this node, or all.
  Control = platform admin, org owner, or operator owning the node.
- nodes.py: legacy raw-ID discord_join now refuses a server outside the node's org.
- discord bot: DirectorySync cog pushes on ready (15-min loop), join/leave,
  rename, voice/category channel changes (debounced).
- frontend: NodeDiscordRadio panel + picker replaces DiscordJoinModal and the
  admin-only Join/Leave buttons.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

drb-server-discord-bot/app/internal/c2_client.py

@@ -68,6 +68,19 @@ class C2Client:
             logger.error(f"C2 stop_guild failed: {e}")
             return None
 
+    async def put_guild_directory(self, guild_id: int | str, payload: dict) -> bool:
+        """This server's name + voice channels, for the web node-page picker
+        (server-26#213). Names only — no members, no messages, no tokens."""
+        try:
+            async with httpx.AsyncClient(timeout=10) as client:
+                r = await client.put(f"{self.base}/discord/guilds/{guild_id}/directory",
+                                     json=payload, headers=self._headers())
+                r.raise_for_status()
+                return True
+        except Exception as e:
+            logger.error(f"C2 put_guild_directory({guild_id}) failed: {e}")
+            return False
+
     # ------------------------------------------------------------------
     # Trips
     # ------------------------------------------------------------------