feat: add board Generate Now smoke spec (M4, skip-if-absent) — v1.5.0

Adds 06-board-generate-now.spec.ts for the PRAutoBlogger board Generate
Now control shipping in v0.21.0 (PR #166). Two tests:

1. Board page loads and #prab-generate-now button is present with nonce.
2. Kick-off AJAX (prautoblogger_generate_now) returns valid JSON — no PHP
   fatal, no wp_send_json_error from a missing nonce.

SKIP-IF-ABSENT: when #prab-board or #prab-generate-now is absent (M4 not
yet deployed) both tests skip with loud annotations so this e2e PR can
merge before prautoblogger PR #166 per the M2/M3 merge-order binding.

READ-ONLY: never waits for generation to complete; kick_off() is
idempotent (guards against duplicate cron scheduling).

Agent-Session: phase2-admin-m4-20260614

package.json

@@ -1,6 +1,6 @@
 {
   "name": "peptide-e2e",
-  "version": "1.4.0",
+  "version": "1.5.0",
   "description": "Playwright smoke tests for peptiderepo.com (staging + production)",
   "private": true,
   "scripts": {