v1.6.1: State-Tracker Refresh + Setup Doc Fixes

Follow-up to v1.6.0 — hook-script and docs fixes, no extension/backend code changes.

Fixed

• Dead setup pointer: scripts/dev.sh and docs/TESTING.md referenced ./plugins/state-tracker/setup.sh, which no longer exists. Both now point at docs/state-tracker-setup.md.
• State-tracker JSON corruption: prompts or paths containing quotes/$ could produce invalid state files (the JSON was built with a heredoc). Now built with jq.
• Subagent counting: moved from PreToolUse Task (which fires even when the Task is denied) to dedicated SubagentStart/SubagentStop hook events.

Added

• Minimal statusline script (docs/scripts/statusline-script.sh) for the context-%-on-tabs feature, plus a new "Context Percentage" section in the setup doc explaining how it links to the state tracker.

Changed

• State-tracker script refreshed (hooks/scripts/state-tracker.sh, docs/scripts/state-tracker.sh): macOS compatibility (stat/md5 fallbacks, mkdir-based locking instead of Linux-only flock), session_title derived from the first prompt, context-window data embedded when a statusline provides it, and expanded stale-file cleanup.

If you installed the state-tracker hooks before: re-copy the script and add the SubagentStart/SubagentStop hook entries from the setup doc to keep subagent counting working.

Full Changelog: v1.6.0...v1.6.1