docs(prd): 0070 expand the consolidated-sidecar arc in the roadmap (#352)

Split the sidecar work into explicit slices: lifecycle (done), build the
real bundle image (done), source-IP-keyed multi-tenant config +
registration/reload (the functional core, next), and routing agent bottles
through it. Renumber firecracker/macos to 8/9. Slices 1-5 implemented
(#352/#356/#357/#358/#360).

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

@@ -325,18 +325,50 @@ orchestrator becomes a VM. Decouple the two risks instead:
   secret handling) is proven with fast iteration — *then* wrap that exact
   service in the VM and solve wiring separately.
 
-Backend order (cheapest proof → hardest → last):
+### Slices
 
-1. **Docker orchestrator** — nearly free (the sidecar bundle is already
-   containers; collapse N bundles into one persistent container). Proves
-   consolidation + the `BottleBackend` seam with the least moving parts.
-2. **Firecracker orchestrator** — the real work: the shim + VM-to-VM
+Built bottom-up as a stack of small PRs off this one (status: **1–5
+implemented** in #352 → #356 → #357 → #358 → #360):
+
+1. **Dev-harness core** ✅ — SQLite registry (runtime state) + fail-closed
+   attribution (source IP + identity token) + the HTTP control plane.
+2. **Launch lifecycle + broker contract** ✅ — `launch_bottle` /
+   `teardown_bottle` + the signed, structured `LaunchBroker` request
+   (HS256 JWT, static ids/flags only, provenance-verified, fail-closed),
+   with a stub broker for the harness and registry rollback on failure.
+3. **Docker launch broker** ✅ — the first real broker: `docker run` / `rm`
+   per bottle, built only from the request's static fields; proves the
+   `BottleBackend` seam on the cheapest backend.
+
+   **The consolidated-sidecar arc** (the core consolidation win — one
+   persistent sidecar shared by all bottles instead of one per bottle):
+
+4. **Sidecar — lifecycle** ✅ — the idempotent-singleton `Sidecar` /
+   `DockerSidecar` (ensure-running is a no-op when already up, stop is
+   idempotent); one container per host.
+5. **Sidecar — build the real bundle image** ✅ — the orchestrator builds
+   the `bot-bottle-sidecars` bundle from `Dockerfile.sidecars` when missing
+   and launches *that* (not a placeholder) as the singleton.
+6. **Sidecar — source-IP-keyed multi-tenant config** — the functional
+   core: the per-bottle CA / egress routes / git-gate keys / policy, today
+   baked per bottle, become **multi-tenant and selected by the verified
+   source IP**, with per-bottle add/remove (live reload) on launch/teardown
+   through the control plane. Until this lands, one shared instance can't
+   serve multiple bottles' distinct policies.
+7. **Sidecar — route agent bottles through it** — wire each agent bottle's
+   egress/git to the shared sidecar (DNAT / network) instead of a per-bottle
+   bundle.
+
+   **Remaining backends** (docker done above; the rest against the proven
+   dev-harness):
+
+8. **Firecracker broker + sidecar** — the real work: the shim + VM-to-VM
    routing (host forwards `bbfcN` → orchestrator TAP; the nft table grows
-   forward rules where today it drops all non-DNAT egress). Built against
-   the dev-harness so the app logic is already proven.
-3. **macOS (Apple container)** — last (container-to-container networking).
+   forward rules where today it drops all non-DNAT egress).
+9. **macOS (Apple container)** — last (container-to-container networking).
 
-Keep the sidecar **service one shared thing** throughout.
+Backends land cheapest-first (docker → firecracker → macOS); keep the
+sidecar **service one shared thing** throughout.
 
 ## Non-goals