Telemetry (#106, #1405)

Role: worker. Manages consent for and reports the local, opt-in telemetry
beacon. The beacon (hooks/telemetry.py) records MINIMAL events — a command
NAME, a skill NAME (including agent-/auto-invoked skills), a gate name +
outcome, and the plugin version — to ~/.claude/metrics/telemetry.jsonl. No
prompts, paths, code, or payloads are ever recorded, and there is no network
egress: everything stays local.

Telemetry is OFF by default. It activates only when the user-level
~/.claude/telemetry.json contains {"enabled": true}. This is a
config-file-only, home-scoped switch: it is read and written at this one path
regardless of which project directory the command runs from.

Scope — keep this small (#106)

This beacon is intentionally a cheap, always-on local counter: which
commands/skills run, how often the commit gate is bypassed. It is not the
self-improvement loop and must not grow into one. The loop is /session-review,
whose digest already extracts a superset of these signals (token, rework,
accuracy, utilization) from transcripts and routes suggestions to governed
machinery. Cross-machine aggregation also belongs to the session-digest
(Delta D / #178), not this beacon. If you find yourself adding analysis or
network egress here, that work belongs in /session-review instead.

Argument: $ARGUMENTS

• status (default): report whether telemetry is enabled and what's collected.
• on: enable by writing ~/.claude/telemetry.json with {"enabled": true}
  (confirm with the user first — this starts local recording).
• off: disable by writing {"enabled": false} (recording stops; the existing
  log is left in place for the user to inspect or delete).
• report: print the usage summary.

Steps

1. status — check ~/.claude/telemetry.json; state on/off, and list
   exactly what is and isn't collected (events: command/skill name, gate
   fired/bypassed, plugin version; never: prompt text, paths, code, network).

2. on / off — write ~/.claude/telemetry.json:

   { "enabled": true }

   For on, confirm consent first. Recording is local-only; the event log
   ~/.claude/metrics/telemetry.jsonl lives outside any project directory so
   it can never be committed.

3. report — summarize the event log:

   python3 "${CLAUDE_PLUGIN_ROOT}/hooks/lib/telemetry_report.py" \
     --log "$HOME/.claude/metrics/telemetry.jsonl"

   Shows command usage, skill usage (including agent-/auto-invoked skills,
   counted distinctly from user-typed commands), and the pre-commit review
   gate's bypass rate. If the log doesn't exist, the report says telemetry is
   off and nothing has left the machine.

Report exactly what the tool emits; do not invent counts.