Switch nick to clod, identify to NickServ, allow #/g/tv

- Nick is now clod with clod_ as fallback; while on a fallback nick the
  server retries NICK clod every nick_retry_seconds (default 180).
- Identify to NickServ whenever holding the configured nick, using the
  password in nickserv_password.txt (gitignored).
- Add #/g/tv to allowed_channels.

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

server.py

@@ -5,7 +5,8 @@ messages, and exposes tools to join/leave/send/read/list users.
 
 It never sends chat text on its own: the only things it writes to the server
 unprompted are protocol traffic (NICK/USER registration, PONG replies,
-keepalive PINGs, and re-joining channels you already joined after a reconnect).
+keepalive PINGs, NickServ IDENTIFY, periodic NICK attempts to reclaim the
+configured nick, and re-joining channels you already joined after a reconnect).
 """
 
 import asyncio
@@ -46,9 +47,24 @@ def load_config() -> dict:
     cfg.setdefault("realname", cfg["nick"])
     cfg.setdefault("allowed_channels", [])
     cfg.setdefault("buffer_size", 200)
+    cfg.setdefault("nickserv_password_file", "")
+    cfg.setdefault("nick_retry_seconds", 180)
     return cfg
 
 
+def nickserv_password(cfg: dict) -> str:
+    """Read the NickServ password from its (gitignored) file, relative to the config."""
+    name = cfg["nickserv_password_file"]
+    if not name:
+        return ""
+    path = CONFIG_PATH.parent / name
+    try:
+        return path.read_text(encoding="utf-8").strip()
+    except FileNotFoundError:
+        log.warning("NickServ password file %s not found; not identifying", path)
+        return ""
+
+
 def irc_lower(s: str) -> str:
     """RFC 1459 case folding, used for channel and nick comparison."""
     return s.lower().translate(str.maketrans("[]\\~", "{}|^"))
@@ -164,6 +180,13 @@ class IRCClient:
         await self.send_raw(f"NICK {self.nick}")
         await self.send_raw(f"USER {cfg['username']} 0 * :{cfg['realname']}")
 
+        reclaim = asyncio.create_task(self._reclaim_nick())
+        try:
+            await self._read_loop(reader)
+        finally:
+            reclaim.cancel()
+
+    async def _read_loop(self, reader: asyncio.StreamReader):
         awaiting_pong = False
         while True:
             try:
@@ -181,6 +204,24 @@ class IRCClient:
             if line:
                 await self._handle(line)
 
+    async def _reclaim_nick(self):
+        """While on a fallback nick, periodically try to switch back to the configured one."""
+        while True:
+            cfg = load_config()
+            await asyncio.sleep(max(30, int(cfg["nick_retry_seconds"])))
+            cfg = load_config()
+            if self.registered.is_set() and not self._is_me(cfg["nick"]):
+                log.info("trying to reclaim nick %s", cfg["nick"])
+                await self.send_raw(f"NICK {cfg['nick']}")
+
+    async def _identify(self):
+        """Identify to NickServ, but only while holding the configured (registered) nick."""
+        cfg = load_config()
+        password = nickserv_password(cfg)
+        if password and self._is_me(cfg["nick"]):
+            log.info("identifying to NickServ as %s", self.nick)
+            await self.send_raw(f"PRIVMSG NickServ :IDENTIFY {password}")
+
     async def _quit(self):
         if self.writer:
             try:
@@ -220,6 +261,7 @@ class IRCClient:
             self.registered.set()
             self.status = f"connected as {self.nick}"
             log.info(self.status)
+            await self._identify()
             for ch in list(self.wanted):
                 await self.send_raw(f"JOIN {self.display.get(ch, ch)}")
         elif cmd in ("432", "433", "436") and not self.registered.is_set():
@@ -267,6 +309,8 @@ class IRCClient:
         elif cmd == "NICK" and p:
             if self._is_me(src):
                 self.nick = p[0]
+                self.status = f"connected as {self.nick}"
+                await self._identify()
             for ch, nicks in self.joined.items():
                 if src in nicks:
                     nicks.discard(src)