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

PROJECT.md

@@ -0,0 +1,37 @@
+# derp - Project
+
+## Purpose
+
+A lightweight, zero-dependency asyncio IRC bot with a clean plugin system for Python 3.11+.
+
+## Architecture
+
+```
+CLI (argparse) -> Config (TOML) -> Bot (orchestrator)
+                                     |-> IRCConnection (async TCP/TLS)
+                                     |-> PluginRegistry (decorators, loader)
+                                           |-> plugins/*.py
+```
+
+### Modules
+
+| Module | Role |
+|--------|------|
+| `cli.py` | Argument parsing, logging setup, entry point |
+| `config.py` | TOML loader with defaults merging |
+| `irc.py` | IRC protocol: message parsing, formatting, async connection |
+| `plugin.py` | Decorator-based plugin system with file loader |
+| `bot.py` | Orchestrator: connect, dispatch, reconnect |
+
+### Key Design Decisions
+
+- **Zero dependencies**: stdlib only (`asyncio`, `ssl`, `tomllib`, `importlib`)
+- **Decorator-based plugins**: `@command` and `@event` for clean registration
+- **File-based plugin loading**: drop `.py` files in `plugins/` directory
+- **Async throughout**: all handlers are `async def`
+
+## Dependencies
+
+- Python 3.11+ (for `tomllib`)
+- No external packages required at runtime
+- Dev: `pytest`, `ruff`