docs(prd): 0070 VM-to-VM routing is not a blocker (#352)

Per review: resolvable at implementation time (host tweak acceptable, as
the pool setup already needs on NixOS); the earlier sidecars-in-VMs spike
showed feasibility. No need to hunt the spike now.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01WBMWTEtQdJ4W5UrWuLHCck

docs/prds/0070-per-host-orchestrator.md

@@ -358,9 +358,10 @@ Keep the sidecar **service one shared thing** throughout.
 
 - **VM-to-VM routing:** per-backend, and in the design it *is*
   `BottleBackend.wire()` (DNAT+forward for fc, shared-net for
-  docker/apple), not orchestrator logic. Likely already prototyped in the
-  earlier "sidecars in VMs" spike — **link the spike** and this drops from
-  open question to "implement per the spike."
+  docker/apple), not orchestrator logic. **Not a blocker** — resolvable at
+  implementation time (may require a bit of host modification, as the pool
+  setup already does on NixOS); an earlier "sidecars in VMs" spike showed
+  it's feasible.
 - **Live-reload protocol** for per-bottle policy over the HTTP control
   plane (add/remove routes/keys/proposals without a restart).
 - **Identity-token delivery:** exactly how the per-bottle token is placed