session-activity-tracker.js is correctly registered in
posttooluse-dispatcher.js's SYNC_HOOKS and fires on every tool call --
but buildActivityRow() only ever read the session id from
ECC_SESSION_ID/CLAUDE_SESSION_ID environment variables, which Claude
Code does not actually set for hook subprocesses. Every row silently
came back null and nothing was ever written to
~/.claude/metrics/tool-usage.jsonl, with no error anywhere.
The session id is available in the hook's own stdin JSON payload
(input.session_id) in real invocations. This prefers that, keeping the
env vars as a fallback. New test added; all 18 existing + new tests
pass.
Also adds a live Activity view to the capabilities dashboard
(scripts/dashboard-web.js) reading that same metrics file, so Skill
vs. Agent vs. raw-tool usage is visible in real time instead of
requiring a manual tail+jq -- verified live against a real session
before this commit. Documents the loopback-only, no-auth design and
the standard SSH-port-forwarding pattern for viewing it from another
device you control.