7e5eeda9a5
Without this, the strip_noise improvement only helps new mines. Every user who had already mined Claude Code JSONL sessions would keep their noise-polluted drawers forever, because convo_miner's file_already_mined skip short-circuits before re-processing. Adds a versioned schema gate so upgrades propagate silently: - palace.NORMALIZE_VERSION=2 — bumped when the normalization pipeline changes shape (this PR's strip_noise is the v1→v2 bump). - file_already_mined now returns False if the stored normalize_version is missing or less than current, triggering a rebuild on next mine. - Both miners stamp drawers with the current normalize_version. - convo_miner now purges stale drawers before inserting fresh chunks (mirrors miner.py's existing delete+insert), extracted into _file_convo_chunks helper to keep mine_convos under ruff's C901 limit. User experience: upgrade mempalace, run `mempalace mine` as usual, old noisy drawers get silently replaced with clean ones. No erase needed, no "you need to rebuild" changelog footgun. Tests: - test_file_already_mined_returns_false_for_stale_normalize_version — pins the version gate contract for missing/v1/current. - test_add_drawer_stamps_normalize_version — fresh project-miner drawers carry the field. - test_mine_convos_rebuilds_stale_drawers_after_schema_bump — end-to-end proof that a pre-v2 palace gets silently cleaned on next mine, with orphan drawers purged and NOT skipped. Existing test_file_already_mined_check_mtime updated to include the new field; all other tests unaffected.