parity: git branch -r -d <missing> (bytes mode)

Closes the last TODO in branch.sh: -r -d against a non-existent
remote-tracking branch. The delete() helper's `remotes` flag flips
the prefix to refs/remotes/ and the not-found row label to
"remote-tracking branch", producing the byte-exact stanza
"error: remote-tracking branch 'origin/nosuch' not found" + exit 1.
Ledger regeneration is a no-op (only the existing compat rows for
--verbose / --abbrev / --column=always remain).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: Mbd06b

tests/journey/parity/branch.sh

@@ -616,8 +616,8 @@ only_for_hash sha1-only && (sandbox
 # hash=sha1-only
 title "gix branch --remotes --delete"
 only_for_hash sha1-only && (small-repo-in-sandbox
-  it "matches git behavior (TODO)" && {
-    : # TODO: expect_parity effect -- branch -r -d origin/nosuch
+  it "matches git behavior" && {
+    expect_parity bytes -- branch -r -d origin/nosuch
   }
 )