v0.10.1 - code-fix never deletes the attempt; names why + attach hint

Fixes two real problems with the v0.10.0 code-fix, both from a live failure (41 findings, Opus ran 17 min, exited 1, and the batch was silently reverted):

• Never delete the work. A failed code-fix used to git restore the touched files, throwing away the attempt. Worse, when the target code is UNTRACKED in the repo (a subtree that was never git added) the restore could only delete newly-created files while leaving modifications, yet still reported "reverted". Now, pass OR fail, the attempt is always left in your working tree - git is the undo. A pass marks the findings fixed; a failure leaves them queued and you review the attempt with git diff, keep the good parts, or discard with git restore . / git stash.
• Say why, and let you inspect it. A failure now names the reason and offers ritual attach <id> to replay the run, instead of a bare "exit 1".
• Dropped the git-based auto-restore and the tree-changed gate (the re-review is the arbiter, and git can't see edits to untracked files anyway). The re-review agent reads the code directly to cover the untracked gap.

Note: for the cleanest verification, keep the code you're fixing inside a git repo (tracked, or its own repo) so the diff is complete.