Agent instructions for `clack.nvim`

Build, test, and lint commands

Run full test suite
- make test
Run a single test file
- nvim --headless --noplugin -u tests/minimal_init.lua -c "PlenaryBustedFile tests/clack/clack_spec.lua"
Lint Lua sources (same check used in CI)
- stylua --check lua

plugin/clack.lua is the runtime entrypoint. It guards against double-load and registers user commands (:ClackEnable, :ClackDisable, :ClackToggle).
lua/clack/init.lua is the orchestrator: it owns plugin state/config, exposes the public API (setup/enable/disable/toggle), routes events to sound pools, and manages enabled/disabled lifecycle.
lua/clack/events.lua owns autocommand wiring. It creates a single augroup and binds:
- InsertCharPre for per-keystroke sounds
- BufWritePost for optional save sounds
lua/clack/profiles.lua defines profile metadata and resolves all sound file paths relative to plugin install root via debug.getinfo + vim.fn.fnamemodify.
lua/clack/audio.lua is the platform backend selector and process launcher:
- macOS: afplay
- Linux: aplay
- Windows: PowerShell System.Media.SoundPlayer
- playback is started via vim.system(..., { detach = true }).

Sound assets follow a strict pool naming convention in sounds/<profile>/:
- key_1.wav ... key_4.wav
- enter_1.wav ... enter_4.wav
- space_1.wav ... space_4.wav
- save_1.wav ... save_4.wav
Enter and space are handled as dedicated sound categories (on_enter, on_space) instead of default key sounds.
Keystroke realism comes from random selection across 4 variations per sound category.
Invalid profile values are surfaced with vim.notify(...) and fallback to cherry_mx_blue.
Tests run through tests/minimal_init.lua, which bootstraps plenary.nvim into runtimepath (default /tmp/plenary.nvim, override with PLENARY_DIR).
Formatting is controlled by .stylua.toml (2-space indentation, max width 120, prefer double quotes).