Fix session.idle to create progressive commits instead of siblings

Auto-chain commits from @- when parent has changes

fix: make jj_push auto-detect push target (@, @-, or further back)

Fix JJ mental model: add docs, enhance jj_push preview, add immutability detection

Update docs: jj new is now automatic on session.idle

Add auto jj-new on session.idle to enforce commit separation

Fix jj_push timing: capture change info before jj new

Add subagent detection and safe jj_push tool

Clean up stale entries in .npmignore

Change workflow: describe at start, jj new at end

Remove unused slash command infrastructure

Checkpoint model: require jj new before every edit, jj undo reverts per-checkpoint

Radically simplify plugin to gate-only mode (~100 lines)

Fix nested workspace bug and add default branch auto-detection

Fix jj_push to show detailed preview in confirmation