feat: initial IRC bouncer implementation

Async Python IRC bouncer with SOCKS5 proxy support, multi-network
connections, password auth, and persistent SQLite backlog with replay.

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

docs/INSTALL.md

@@ -0,0 +1,42 @@
+# Installation
+
+## Prerequisites
+
+- Python 3.10+
+- SOCKS5 proxy running on `127.0.0.1:1080`
+
+## Setup
+
+```bash
+cd ~/git/bouncer
+make dev
+```
+
+This creates `.venv/`, installs dependencies, and registers the `bouncer` command.
+
+## Verify
+
+```bash
+bouncer --version
+```
+
+## Configuration
+
+```bash
+cp config/bouncer.example.toml config/bouncer.toml
+```
+
+Edit `config/bouncer.toml` with your network details. At minimum, set:
+
+- `bouncer.password` -- client authentication password
+- `networks.<name>.host` -- IRC server hostname
+- `networks.<name>.nick` -- your IRC nickname
+- `networks.<name>.channels` -- channels to auto-join
+
+## Symlink
+
+The `make dev` editable install registers `bouncer` in `.venv/bin/`. To make it available system-wide:
+
+```bash
+ln -sf ~/git/bouncer/.venv/bin/bouncer ~/.local/bin/bouncer
+```