📝 Correct the upstream claim in branch.sh

`main` tracks `origin` (ssh); the comment claiming it tracked an
https companion remote was stale.

scripts/branch.sh

@@ -73,9 +73,9 @@ git show-ref --verify --quiet "refs/heads/${BASE}" || {
     exit 1
 }
 
-# Derive the remote rather than hardcoding it: this repo has `origin` (ssh) and
-# `origin_https`, and `main` tracks the latter — `git fetch origin main` would
-# check currency against a ref that is never updated here.
+# Derive the remote rather than hardcoding it: `main` tracks `origin` (ssh)
+# here; a hardcoded name would check currency against a ref that may not
+# exist on a differently configured clone.
 # `--quiet` echoes the unresolved `main@{upstream}` literal to stdout on
 # failure, so it cannot be paired with a `$(...) || fallback`; the non-quiet
 # form prints nothing on failure and the fallback runs.