feat(orchestrator+egress): slice 8 — multi-tenant egress via the resolver (#352)

The egress addon now selects each request's Config by the calling bottle's
source IP, so one shared sidecar serves every bottle. Opt-in and fail-closed;
single-tenant behaviour is unchanged.

Orchestrator side (source-IP-primary attribution, per the PRD invariant):
  * registry: `by_source_ip` (the single active bottle at a source IP —
    network-layer attribution); `attribute` now composes it + the token.
  * service: `resolve(source_ip, token="")` — with a token, strict
    attribution; without, source IP alone.
  * control_plane: `POST /resolve`'s identity_token is now OPTIONAL (absent
    → source-IP-only); split cleanly from the token-required `/attribute`.
  * policy_resolver: `resolve` token now optional.

Egress side:
  * egress_addon_core: `resolve_client_config(resolver, client_ip, token)` —
    fetches + parses the client's Config, **fail-closed**: unattributed, a
    resolver error, or an unparseable policy all yield deny-all (no routes).
    Host-testable; `PolicyResolverLike` Protocol keeps it import-free.
  * egress_addon: consolidated mode when `BOT_BOTTLE_ORCHESTRATOR_URL` is
    set → `_active_config(flow)` resolves per client IP (reads + strips the
    `x-bot-bottle-identity` header); `request()` uses it. Unset → the static
    routes file, exactly as before. `PolicyResolver` added to the bundle.

Security note: source-IP-only resolution is safe where the IP is unspoofable
(Firecracker /31 + nft) AND the control plane is reachable only by the
trusted sidecar; the identity token, when the agent injects it, strengthens
it on weaker backends.

Scope note: the egress data plane is now multi-tenant. Remaining to be fully
live: the network topology routing every bottle's proxy to the one shared
sidecar, git-gate multitenancy, and agent-side identity-token injection.

Tests: registry by_source_ip; orchestrator resolve (with/without token);
control-plane /resolve token-optional; resolver token-optional;
resolve_client_config fail-closed matrix. All 182 egress tests still pass
(single-tenant unchanged). Full suite green.

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

tests/unit/test_orchestrator_registry.py

@@ -121,6 +121,18 @@ class TestRegistryStore(unittest.TestCase):
         assert got is not None
         self.assertEqual("", got.policy)
 
+    def test_by_source_ip_returns_single_active(self) -> None:
+        rec = self.store.register("10.243.0.1")
+        got = self.store.by_source_ip("10.243.0.1")
+        assert got is not None
+        self.assertEqual(rec.bottle_id, got.bottle_id)
+
+    def test_by_source_ip_unknown_or_ambiguous_denied(self) -> None:
+        self.assertIsNone(self.store.by_source_ip("10.243.9.9"))  # unknown
+        self.store.register("10.243.0.1", bottle_id="a")
+        self.store.register("10.243.0.1", bottle_id="b")
+        self.assertIsNone(self.store.by_source_ip("10.243.0.1"))  # ambiguous
+
 
 if __name__ == "__main__":
     unittest.main()