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/DEBUG.md

@@ -0,0 +1,74 @@
+# Debugging
+
+## Verbose Mode
+
+```bash
+derp --verbose
+```
+
+Shows all IRC traffic:
+
+```
+>>> NICK derp
+>>> USER derp 0 * :derp IRC bot
+<<< :server 001 derp :Welcome
+>>> JOIN #test
+```
+
+## Log Levels
+
+Set in `config/derp.toml`:
+
+```toml
+[logging]
+level = "debug"    # debug, info, warning, error
+```
+
+## Common Issues
+
+### Connection refused
+
+```
+ERROR derp.irc  connection lost: [Errno 111] Connection refused
+```
+
+- Check `host` and `port` in config
+- Verify TLS setting matches port (6697 = TLS, 6667 = plain)
+- Test connectivity: `nc -zv <host> <port>`
+
+### Nickname in use
+
+The bot appends `_` to the nick and retries automatically. Check logs for:
+
+```
+<<< :server 433 * derp :Nickname is already in use
+>>> NICK derp_
+```
+
+### TLS certificate errors
+
+If the server uses a self-signed certificate, you may need to adjust the SSL context. Currently uses system default CA bundle.
+
+### Plugin load failures
+
+```
+ERROR derp.plugin  failed to load plugin: plugins/broken.py
+```
+
+- Check plugin file for syntax errors: `python -c "import plugins.broken"`
+- Ensure handlers are `async def`
+- Check imports (`from derp.plugin import command, event`)
+
+### No response to commands
+
+- Verify `prefix` in config matches what you type
+- Check that the plugin is loaded (look for "loaded plugin" in verbose output)
+- Ensure the bot has joined the channel
+
+## Testing IRC Connection
+
+```bash
+# Test raw IRC (without the bot)
+openssl s_client -connect irc.libera.chat:6697
+# Then type: NICK testbot / USER testbot 0 * :test
+```