fix(git-gate): reject AGit review refs

bot_bottle/gateway/git_gate/render.py

@@ -252,6 +252,23 @@ cat > "$refs_file"
 
 zero=0000000000000000000000000000000000000000
 
+# AGit creates pull requests by pushing to refs/for/* (with refs/draft/*
+# and refs/for-review/* aliases). Those server-owned review refs are not
+# ordinary repository branches and leave the resulting PR without a
+# branch that the bottle can update later. Require the normal
+# push-branch-then-open-PR workflow instead. Deletion remains allowed so
+# operators can clean up refs created before this guard existed.
+while IFS=' ' read -r old new ref; do
+  [ -z "$ref" ] && continue
+  [ "$new" = "$zero" ] && continue
+  case "$ref" in
+    refs/for/*|refs/draft/*|refs/for-review/*)
+      echo "git-gate: AGit review refs are disabled; push to refs/heads/<branch> and open the pull request from that branch" >&2
+      exit 1
+      ;;
+  esac
+done < "$refs_file"
+
 supervise_gitleaks_allow() {
   log_opts=$1
   ref=$2

tests/unit/test_git_gate.py

@@ -181,6 +181,21 @@ class TestHookRender(unittest.TestCase):
         self.assertNotIn('log_opts="$new"', hook)
         self.assertNotIn('log_opts="$old..$new"', hook)
 
+    def test_agit_review_refs_are_rejected_before_scanning(self):
+        hook = git_gate_render_hook()
+        guard = "refs/for/*|refs/draft/*|refs/for-review/*"
+        self.assertIn(guard, hook)
+        self.assertIn(
+            "AGit review refs are disabled; push to refs/heads/<branch>",
+            hook,
+        )
+        self.assertLess(hook.index(guard), hook.index("# Phase 1: gitleaks"))
+        # Ref deletion must remain possible for cleanup.
+        self.assertLess(
+            hook.index('[ "$new" = "$zero" ] && continue'),
+            hook.index(guard),
+        )
+
     def test_forward_ssh_is_non_interactive_and_bounded(self):
         # No prompt (BatchMode) and a connect timeout, so an unreachable
         # upstream fails fast instead of hanging the receive-pack.