suggest-compact: counter temp files never cleaned up, and count resets every /compact

[jbegarek]

Summary

Two small, related issues with the counter file in scripts/hooks/suggest-compact.js.

1. Counter temp files are never cleaned up

Each session writes claude-tool-count-<sessionId> into the temp dir (getTempDir()), and nothing ever removes it. Over time these accumulate — at least one file per session, indefinitely.

Suggestion: sweep on run — delete claude-tool-count-* files older than N days (env-tunable, e.g. COMPACT_STATE_TTL_DAYS, default 14) at the start of main(). Cheap and keeps the temp dir bounded.

2. The count resets on every /compact

The counter is keyed on session_id, which rotates when a session is compacted or resumed. So the "50 calls, then every 25" cadence restarts from zero after each /compact. In compact-heavy / long multi-phase workflows the count signal often never reaches the threshold, which is ironic for a compaction helper.

Suggestion: key the cumulative count on something stable across compaction — e.g. project path + calendar day (claude-tool-count-<projHash>-<YYYYMMDD>) — so it survives the session-id rotation. (A context-size signal, proposed separately in #2155, would address window pressure more robustly regardless of count.)

Both are minor; happy to PR either or both.

_{Filed after auditing a local copy of the skill; surfaced via Claude Code.}