feat: enable daily CNPG Option A backup on railiance01

Wire worker kubeconfig hostPath (no PATH override), enable
daily-cnpg-option-a-backup for R01 targets, ESO already synced.

src/activity_core/context_resolvers/cnpg_backup.py

@@ -26,10 +26,10 @@ def cnpg_option_a_backup(params: dict[str, Any]) -> dict[str, Any]:
     targets = params.get("targets")  # optional CSV
 
     env = os.environ.copy()
-    # Ensure vendor bin (age/kubectl) is visible when hostPath is mounted.
+    # Prepend vendor bin (age/kubectl) without wiping the image PATH/venv.
     vendor = Path("/opt/railiance-platform/tools/vendor/bin")
     if vendor.is_dir():
-        env["PATH"] = f"{vendor}:{env.get('PATH', '')}"
+        env["PATH"] = f"{vendor}:{env.get('PATH', '/usr/local/bin:/usr/bin:/bin')}"
 
     if dry_run:
         env["RAILIANCE_BACKUP_DRY_RUN"] = "1"