feat: add IRCv3 cap negotiation, channel management, state persistence

Implement CAP LS 302 flow with configurable ircv3_caps list, replacing
the minimal SASL-only registration. Parse IRCv3 message tags (@key=value)
with proper value unescaping. Add channel management plugin (kick, ban,
unban, topic, mode) and bot API methods. Add SQLite key-value StateStore
for plugin state persistence with !state inspection command.

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

plugins/chanmgmt.py

@@ -0,0 +1,81 @@
+"""Channel management: kick, ban, unban, topic, mode."""
+
+from derp.plugin import command
+
+
+def _require_channel(message):
+    """Return True if the message originated in a channel."""
+    return message.is_channel
+
+
+@command("kick", help="Kick a user: !kick <nick> [reason]", admin=True)
+async def cmd_kick(bot, message):
+    """Kick a user from the current channel."""
+    if not _require_channel(message):
+        await bot.reply(message, "Must be used in a channel")
+        return
+    parts = message.text.split(None, 2)
+    if len(parts) < 2:
+        await bot.reply(message, "Usage: !kick <nick> [reason]")
+        return
+    nick = parts[1]
+    reason = parts[2] if len(parts) > 2 else ""
+    await bot.kick(message.target, nick, reason)
+
+
+@command("ban", help="Ban a hostmask: !ban <mask>", admin=True)
+async def cmd_ban(bot, message):
+    """Set +b on a hostmask in the current channel."""
+    if not _require_channel(message):
+        await bot.reply(message, "Must be used in a channel")
+        return
+    parts = message.text.split(None, 1)
+    if len(parts) < 2:
+        await bot.reply(message, "Usage: !ban <mask>")
+        return
+    mask = parts[1]
+    await bot.mode(message.target, "+b", mask)
+
+
+@command("unban", help="Remove a ban: !unban <mask>", admin=True)
+async def cmd_unban(bot, message):
+    """Remove +b from a hostmask in the current channel."""
+    if not _require_channel(message):
+        await bot.reply(message, "Must be used in a channel")
+        return
+    parts = message.text.split(None, 1)
+    if len(parts) < 2:
+        await bot.reply(message, "Usage: !unban <mask>")
+        return
+    mask = parts[1]
+    await bot.mode(message.target, "-b", mask)
+
+
+@command("topic", help="Set or query channel topic: !topic [text]", admin=True)
+async def cmd_topic(bot, message):
+    """Set or query the channel topic."""
+    if not _require_channel(message):
+        await bot.reply(message, "Must be used in a channel")
+        return
+    parts = message.text.split(None, 1)
+    if len(parts) < 2:
+        # Query current topic
+        from derp.irc import format_msg
+        await bot.conn.send(format_msg("TOPIC", message.target))
+    else:
+        await bot.set_topic(message.target, parts[1])
+
+
+@command("mode", help="Set channel mode: !mode <mode> [args]", admin=True)
+async def cmd_mode(bot, message):
+    """Set a mode on the current channel."""
+    if not _require_channel(message):
+        await bot.reply(message, "Must be used in a channel")
+        return
+    parts = message.text.split(None)
+    if len(parts) < 2:
+        await bot.reply(message, "Usage: !mode <mode> [args]")
+        return
+    mode_str = parts[1]
+    args = parts[2:]
+    await bot.mode(message.target, mode_str, *args)

plugins/core.py

@@ -163,3 +163,57 @@ async def cmd_admins(bot, message):
     else:
         parts.append("Opers: (none)")
     await bot.reply(message, " | ".join(parts))
+
+
+@command("state", help="Inspect plugin state: !state <list|get|del|clear> ...", admin=True)
+async def cmd_state(bot, message):
+    """Manage the plugin state store.
+
+    Usage:
+        !state list <plugin>          List keys
+        !state get <plugin> <key>     Get a value
+        !state del <plugin> <key>     Delete a key
+        !state clear <plugin>         Clear all state
+    """
+    parts = message.text.split()
+    if len(parts) < 3:
+        await bot.reply(message, "Usage: !state <list|get|del|clear> <plugin> [key]")
+        return
+
+    action = parts[1].lower()
+    plugin = parts[2]
+
+    if action == "list":
+        keys = bot.state.keys(plugin)
+        if keys:
+            await bot.reply(message, f"{plugin}: {', '.join(keys)}")
+        else:
+            await bot.reply(message, f"{plugin}: (no keys)")
+
+    elif action == "get":
+        if len(parts) < 4:
+            await bot.reply(message, "Usage: !state get <plugin> <key>")
+            return
+        key = parts[3]
+        value = bot.state.get(plugin, key)
+        if value is not None:
+            await bot.reply(message, f"{plugin}.{key} = {value}")
+        else:
+            await bot.reply(message, f"{plugin}.{key}: not set")
+
+    elif action == "del":
+        if len(parts) < 4:
+            await bot.reply(message, "Usage: !state del <plugin> <key>")
+            return
+        key = parts[3]
+        if bot.state.delete(plugin, key):
+            await bot.reply(message, f"Deleted {plugin}.{key}")
+        else:
+            await bot.reply(message, f"{plugin}.{key}: not found")
+
+    elif action == "clear":
+        count = bot.state.clear(plugin)
+        await bot.reply(message, f"Cleared {count} key(s) from {plugin}")
+
+    else:
+        await bot.reply(message, "Usage: !state <list|get|del|clear> <plugin> [key]")