* fix(git): share one error-text reader between the local and relay branch-delete fallbacks
The relay and the desktop each carried their own `getErrorText`, and they had
drifted: the relay read `message` + `stderr` + `stdout`, the desktop only
`message` + `stderr`. A `git branch -d` refusal arriving on `stdout` therefore
routed the SSH removal through prune-and-retry while the local removal gave up
and preserved the branch.
Against a real binary the two agree, because Git prints the refusal through
`error()` on every supported version — verified on 2.25.1, 2.38.1, 2.49.1 and
2.55.0, none of which put a byte of it on stdout. What the desktop copy actually
missed is that Orca classifies errors it built itself, with the Git output on
`.stdout`: `worktree remove`'s submodule retry attaches `git status --porcelain`
that way on both paths. The stdout-reading form is also already the shared
spelling — `isSubmoduleWorktreeRemovalRefusal` uses it for both hosts — so this
converges on it rather than on the shorter one.
Move the reader to src/shared/git-command-failure-text.ts and the predicate it
feeds to src/shared/git-branch-delete-refusal.ts, and delete all three copies.
The predicate carries both refusal wordings live in the supported range: Git
through 2.40 says "checked out at", 2.43+ says "used by worktree at".
The real-binary contract now pins that boundary: the refusal is recognized, it
lands on stderr, and stdout stays empty on every Git in the matrix.
* fix(test): consolidate the duplicate worktree import in the parity test
