jj conflict and bookmark workflow

In .jj/ repositories, use non-interactive Jujutsu for mutations, always pass -m, prefer stable change IDs, and verify every mutation with jj st plus jj log. Trap: expecting rebase, new, or squash to fail on conflicts looks right because Git does, but Jujutsu records conflicts in the resulting commit; manually edit markers and verify with jj st, never interactive jj resolve. jj commit leaves an empty @ and committed content at @-; bookmarks do not advance, so run jj bookmark set <name> -r @-. Avoid immutable revisions; recover with jj undo, jj op log, or jj op restore.