fix: register the hook as PostToolUse so it actually fires

[quad341]

The bug

codachi init writes the hook into ~/.claude/settings.json like this:

"hooks": {
  "PostToolExecution": [
    { "matcher": "", "command": "codachi-hook" }
  ]
}

Two problems: Claude Code has no PostToolExecution event (it's PostToolUse), and a matcher entry carries its commands in a nested hooks: [{type, command}] array rather than a flat command key.

The result is a hook that never runs. Claude Code ignores the unknown event, codachi-hook is never invoked, nothing is ever appended to events.json, and the mood engine has no events to read — so pets sit on idle/context messages forever and none of the ~40 event categories or the reactions built on them ever surface. It fails silently: the install prints success and the statusline renders fine, which is presumably why it went unnoticed.

CLAUDE.md already documents the data flow as PostToolUse, so this looks like a straightforward slip in init.ts rather than a deliberate choice.

The fix

• init writes PostToolUse with the nested hooks array and matcher: "*".
• init also drops any stale codachi entry left under PostToolExecution, so existing users are migrated by re-running codachi init — no manual settings editing.
• uninstall cleans up both event names.
• Both paths recognise the flat legacy shape and the nested one, and leave other tools' hooks (and other events) untouched.
• Docs updated: README.md manual-setup block and prose, CLAUDE.md, hook.ts header.

Verification

src/init.test.ts is new — 14 tests covering the written shape, statusLine, idempotent re-init, legacy migration, preservation of foreign hooks and unrelated settings, local-clone absolute paths, and the uninstall paths including the no-op cases.

Full suite: 375 passed (20 files), tsc --noEmit clean.

Also verified end-to-end against a throwaway $HOME containing a legacy install plus an unrelated PreToolUse hook: init migrated it to PostToolUse, left the foreign hook alone, and uninstall removed only codachi's entry.

I'm running this fix locally and the hook now records events as expected.

🤖 Generated with Claude Code

https://claude.ai/code/session_018sFUvWzeRmjzQGDUsLnYgY