feat(run): the repository under review is the freeze record's, not the working directory's

A directory can review repositories other than itself: a workbench whose
config, env file and records serve several, freezing each with --repo and
--out. The run took the working directory for the repository under review:
the prompt named it, the calibration was kept under it, and --trees fell
back to it. The run now reads the repository from the artifact's
freeze.json - the prompt names it and the calibration is kept under it -
and --trees defaults to what the record says: the worktree, else the
repository when it is not the working directory, else `.`, the same rule
that builds the printed run line. The working directory keeps its roles:
the config, the env file, the slots, the lens processes' cwd and every
logged path. A damaged record stops the run at preflight.

process/prepush.md

@@ -27,7 +27,9 @@ hash at Gate 5.
 - The repository at the range HEAD: the checkout itself (`--trees .`; the
   driver verifies HEAD and a clean tree before every launch) or a detached
   worktree under `.review-gates/trees/<repo>-<hash8>/` (`freeze --worktree`;
-  gitignored) — content, history and blame; the state before the range via
+  gitignored; `--trees` defaults to what the freeze record says, so a
+  workbench that froze another repository with `--repo` reads its worktree)
+  — content, history and blame; the state before the range via
   `git show <base>:<path>`.
 - `--context-paths` for the evidence dirs the commit messages' claims rest on.
 - The lens charter (`process/lenses/repo-*.md`, system text