fix(agent): normalize Windows updater paths

manifest.json

@@ -1,6 +1,6 @@
 {
   "pack_id": "gewu-research",
-  "pack_version": "0.20.12",
+  "pack_version": "0.20.13",
   "manifest_version": "1.0.0",
   "status": "local-contract-and-checkpoint-bound-hosts-not-qualified",
   "execution": "existing-local-agent-host",
@@ -397,7 +397,7 @@
       "compatible_checkpoint_contracts": [
         "gewu.local-checkpoint@0.1.0"
       ],
-      "sha256": "964fc6944b63e457855f558182cf3ab83c9c3bebc8fa6448087e3072a3f821d0",
+      "sha256": "81a67a3bdf9515831575405de7a3ea686e9ee9bcec14c04a8da9ced360324b89",
       "hash_encoding": "utf8-no-bom-lf"
     },
     {
@@ -516,6 +516,6 @@
   "snapshot": {
     "algorithm": "sha256",
     "scope": "modules array serialized as UTF-8 JSON with sorted keys and compact separators",
-    "digest": "54f6dd1e9fbb9b3e7dcf4de99d43df36dd06cd796afa65a510df5978e6cee6f5"
+    "digest": "80cc9e1aecbec05a369291e79dfe94ddea87bfc418965e421b6fa75b7bf4bdc9"
   }
 }