feat(freeze): crafter-review freeze, and --verify that names a git upgrade

Freeze: identity, AI trailers by the consumer's rule (the pattern with
case-insensitive folds and its \s* that crosses lines), a clean tree, no
merges, a fast-forward, then format-patch, the hash, the dispositions
register and the optional detached worktree; --verify at push time. The
command line takes --opt=value, unique prefixes and the last of a repeat,
with a usage error at exit 3 like every command that cannot start; the
config is loaded and its warnings and problems reported first. The run
line it prints names this binary.

freeze.json records gitVersion. format-patch ends every patch with the
git version, so a fresh export under another git hashes differently;
--verify's MISMATCH says which git exported the artifact and which the
fresh copy, reading the patches' own signature when freeze.json does not
record it. freeze becomes a subreaper and takes down whatever gpg left
running for %G?.

tests/Freeze: 18 checks, plus the gitVersion record and both MISMATCH
messages.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

interfaces/Crafter.Review.cppm

@@ -22,4 +22,5 @@ export import :PgWire;
 export import :Stream;
 export import :Prompt;
 export import :Config;
+export import :Freeze;
 export import :Driver;