feat: initial implementation

Asyncio IRC bot with decorator-based plugin system.
Zero external dependencies, Python 3.11+.

- IRC protocol: message parsing, formatting, async TCP/TLS connection
- Plugin system: @command and @event decorators, file-based loading
- Bot orchestrator: connect, dispatch, reconnect, nick recovery
- CLI: argparse entry point with TOML config
- Built-in plugins: ping, help, version, echo
- 28 unit tests for parser and plugin system

docs/CHEATSHEET.md

@@ -0,0 +1,59 @@
+# Cheatsheet
+
+## Quick Commands
+
+```bash
+make install          # Setup venv + install
+make test             # Run tests
+make lint             # Lint with ruff
+make run              # Start bot
+make link             # Symlink to ~/.local/bin
+derp -c config.toml   # Run with custom config
+derp -v               # Verbose/debug mode
+```
+
+## Bot Commands
+
+```
+!ping              # Pong
+!help              # List commands
+!help <cmd>        # Command help
+!version           # Bot version
+!echo <text>       # Echo text back
+```
+
+## Plugin Template
+
+```python
+from derp.plugin import command, event
+
+@command("name", help="Description")
+async def cmd_name(bot, message):
+    text = message.text.split(None, 1)
+    await bot.reply(message, "response")
+
+@event("JOIN")
+async def on_join(bot, message):
+    await bot.send(message.target, f"Hi {message.nick}")
+```
+
+## Message Object
+
+```
+msg.nick        # Sender nick
+msg.target      # Channel or nick
+msg.text        # Message body
+msg.is_channel  # True if channel
+msg.prefix      # nick!user@host
+msg.command     # PRIVMSG, JOIN, etc.
+msg.params      # All params list
+```
+
+## Config Locations
+
+```
+1. --config PATH              # CLI flag
+2. ./config/derp.toml         # Project dir
+3. ~/.config/derp/derp.toml   # User config
+4. Built-in defaults          # Fallback
+```