feat: add --no-test flag to prepare-gates

Allows skipping the full test suite during prepare phase.
Testing is deferred to the dedicated Test phase in the pipeline.

scripts/pr

@@ -1384,6 +1384,7 @@ validate_changelog_merge_hygiene() {
 
 prepare_gates() {
   local pr="$1"
+  local skip_test="${2:-false}"
   enter_worktree "$pr" false
 
   checkout_prep_branch "$pr"
@@ -1418,7 +1419,9 @@ prepare_gates() {
   run_quiet_logged "pnpm build" ".local/gates-build.log" pnpm build
   run_quiet_logged "pnpm check" ".local/gates-check.log" pnpm check
 
-  if [ "$docs_only" = "true" ]; then
+  if [ "$skip_test" = "true" ]; then
+    echo "Test skipped (--no-test). Full suite deferred to Test phase."
+  elif [ "$docs_only" = "true" ]; then
     echo "Docs-only change detected with high confidence; skipping pnpm test."
   else
     run_quiet_logged "pnpm test" ".local/gates-test.log" pnpm test
@@ -1987,7 +1990,7 @@ main() {
       prepare_validate_commit "$pr"
       ;;
     prepare-gates)
-      prepare_gates "$pr"
+      prepare_gates "$pr" "${3:-false}"
       ;;
     prepare-push)
       prepare_push "$pr"

scripts/pr-prepare

@@ -1,13 +1,20 @@
 #!/usr/bin/env bash
 set -euo pipefail
 
-if [ "$#" -ne 2 ]; then
-  echo "Usage: scripts/pr-prepare <init|validate-commit|gates|push|run> <PR>"
+if [ "$#" -lt 2 ]; then
+  echo "Usage: scripts/pr-prepare <init|validate-commit|gates|push|run> <PR> [--no-test]"
   exit 2
 fi
 
 mode="$1"
 pr="$2"
+shift 2
+no_test=false
+for arg in "$@"; do
+  case "$arg" in
+    --no-test) no_test=true ;;
+  esac
+done
 script_dir="$(cd "$(dirname "$0")" && pwd)"
 base="$script_dir/pr"
 if common_git_dir=$(git -C "$script_dir" rev-parse --path-format=absolute --git-common-dir 2>/dev/null); then
@@ -25,7 +32,11 @@ case "$mode" in
     exec "$base" prepare-validate-commit "$pr"
     ;;
   gates)
-    exec "$base" prepare-gates "$pr"
+    if [ "$no_test" = "true" ]; then
+      exec "$base" prepare-gates "$pr" true
+    else
+      exec "$base" prepare-gates "$pr"
+    fi
     ;;
   push)
     exec "$base" prepare-push "$pr"