feat(controller-peers-env-fallback): keep existing no-peers test scripts on the path they test (task 5.2)

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

.kiro/specs/controller-peers-env-fallback/tasks.md

@@ -102,7 +102,7 @@
   - Done when, with the xceadmin wheel built (`/xce-build xceadmin`), the wrapper case in the regression script passes
   - _Requirements: 4.1, 4.2_
 
-- [ ] 5.2 Keep existing no-peers test scripts on the path they test
+- [x] 5.2 Keep existing no-peers test scripts on the path they test
   - Both scripts delete their scheduler log on exit, so each must check the path itself: first add a check that greps its scheduler log for the "No --peers flag ... XCE_CONTROLLER_PEERS unset or empty" line and fails the script if it is missing, and see it fail with the variable set in the calling shell
   - Then add `unset XCE_CONTROLLER_PEERS` near the top of the version-startup-consistency and dirty-fingerprint-startup-log scripts, which start the scheduler without `--peers`
   - Done when, with the variable set in the calling shell, both scripts pass, including their new no-peers-line check
@@ -139,3 +139,4 @@
 - (3.1 → 5.2) On this machine `test-version-startup-consistency.sh` and `test-dirty-fingerprint-startup-log-unchanged.sh` exit 1 for an environmental reason: their apiserver `go build` fails with "module lookup disabled by GOPROXY=off" (no Go module cache). Their scheduler checks pass. Task 5.2's "both scripts pass" needs a machine with the Go module cache, or the result must be reported as environment-limited with the scheduler checks shown passing.
 - (3.2) The worker's early stdout lines are not buffered (visible within 0.3s while it runs). `xcecd_virtual` ignores SIGTERM (pre-existing), so `start_worker` SIGKILLs it after the asserted line; the virtual worker leaves only its scratch log. Its peers parse/validation early returns now free `logdir` (they leaked under ASAN). Out of scope, pre-existing: `-l <dir>` combined with `-h`/`--version` still leaks `logdir`.
 - (3.2 → 3.3) The file-wide `shellcheck disable=SC2329` must stay (cases and helpers run via the `"$fn"` registry and `trap`); the SC2034 disable now covers only the `HARNESS_BIN` line — remove it once the harness cases use it.
+- (5.2) Environment-limited completion: the new `[scheduler-no-peers]` check passes in both scripts with the variable set and unset (RED reproduced: with the variable set and no `unset`, the scheduler took the HA path and the check failed). Neither script exits 0 here: both stop at the apiserver `go build` (GOPROXY=off, no Go module cache), and `test-version-startup-consistency.sh` also fails its scheduler commit-id check on any dirty tree — pre-existing, logged as bug-1909. A full pass of both scripts still needs a machine with the Go module cache and a clean tree (or a bug-1909 fix); carry this into 5.3.

src/tools/test-dirty-fingerprint-startup-log-unchanged.sh

@@ -89,6 +89,10 @@
 #     composeVersionDisplay()'s strings.TrimSuffix() call.
 set -euo pipefail
 
+# The scheduler below starts without --peers; keep a caller's XCE_CONTROLLER_PEERS
+# from moving it off the single-controller path this script tests.
+unset XCE_CONTROLLER_PEERS
+
 # ── paths ───────────────────────────────────────────────────────────────────
 SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
 WORKTREE="$(cd "$SCRIPT_DIR/../.." && pwd)"
@@ -471,6 +475,12 @@ if [ -z "$sched_log_line" ]; then
     overall_pass=0
 else
     yellow "[scheduler] startup log line: [$sched_log_line]"
+    if grep -F -- "No --peers flag" "$sched_log" | grep -qF -- "XCE_CONTROLLER_PEERS unset or empty"; then
+        green "PASS [scheduler-no-peers]: scheduler took the single-controller path (no --peers, XCE_CONTROLLER_PEERS unset)."
+    else
+        red "FAIL [scheduler-no-peers]: scheduler log has no 'No --peers flag ... XCE_CONTROLLER_PEERS unset or empty' line -- it did not take the single-controller path this script tests."
+        overall_pass=0
+    fi
     if [ -n "$sched_fp" ]; then
         if ! assert_startup_log_unchanged "scheduler-startup-log" "$sched_log_line" "sched" "$base_commit" "$sched_fp"; then
             overall_pass=0

src/tools/test-version-startup-consistency.sh

@@ -103,6 +103,10 @@
 #     "********** Initialize Logger done!" log message in the same file.
 set -euo pipefail
 
+# The scheduler below starts without --peers; keep a caller's XCE_CONTROLLER_PEERS
+# from moving it off the single-controller path this script tests.
+unset XCE_CONTROLLER_PEERS
+
 # ── paths ───────────────────────────────────────────────────────────────────
 SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
 WORKTREE="$(cd "$SCRIPT_DIR/../.." && pwd)"
@@ -323,6 +327,12 @@ if [ -z "$sched_log_line" ]; then
     sched_v_commit=""; sched_v_build=""
 else
     yellow "[scheduler] startup log line: [$sched_log_line]"
+    if grep -F -- "No --peers flag" "$sched_log" | grep -qF -- "XCE_CONTROLLER_PEERS unset or empty"; then
+        green "PASS [scheduler-no-peers]: scheduler took the single-controller path (no --peers, XCE_CONTROLLER_PEERS unset)."
+    else
+        red "FAIL [scheduler-no-peers]: scheduler log has no 'No --peers flag ... XCE_CONTROLLER_PEERS unset or empty' line -- it did not take the single-controller path this script tests."
+        overall_pass=0
+    fi
 
     if ! sched_v_fields="$(extract_composed_fields "$sched_version_raw" "$SCHED_VERSION_PREFIX")"; then
         red "FAIL [scheduler]: --version output did not contain the expected prefix '$SCHED_VERSION_PREFIX' -- raw: [$sched_version_raw]"