hub v0.13.1 — DR recipe v1 drive-shape sync (test-data + regression guard only)

Tracks felhom-agent v0.39.0, which dropped role + restic_repo_coord from the host-half
drives[]. Hub reads drives as json.RawMessage (verbatim passthrough) → no store/handler
change needed. Dropped role from the store golden + drHostHalf fixture; re-synced the api
host-report golden byte-identical with the agent copy (it previously lacked dr_recipe
entirely). Added TestAssembleDRRecipe_V1DriveShape regression guard (demonstrated to fail
when the fixture re-adds role, then reverted). No behavior change; redeploy optional.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

hub/internal/store/testdata/dr-recipe.golden.json

@@ -8,7 +8,6 @@
   "drives": [
     {
       "durable_id": "uuid:da9e7089-cf8e-4617-adcb-a377743fae00",
-      "role": "bulk-data",
       "mount_path": "/mnt/felhom-usb",
       "intent": "enrolled",
       "total_bytes": 1000000000000