fix(egress+orchestrator): inject per-bottle auth tokens in the shared gateway

The cut-over dropped the per-bottle token flow, so an authed egress route on
the shared gateway failed with 'env var EGRESS_TOKEN_0 is unset' — the gateway
reads the token from its env, but a shared gateway has no per-bottle env.

Now the bottle's egress auth tokens travel to the gateway over /resolve and
the addon injects from them, mirroring what the per-bottle sidecar's env did:
- launch resolves the token values from the host env and hands them to the
  orchestrator, which holds them IN MEMORY (keyed by bottle_id, never written
  to the registry DB) and serves them on /resolve;
- PolicyResolver.resolve_policy_and_bottle_id + resolve_client_context now
  return the token map alongside policy + bottle_id (one round-trip);
- the egress addon overlays the process env with the bottle's tokens per
  request and uses that env for auth injection AND DLP — the agent never sees
  the credential.

Secrets stay off disk (validated: /resolve returns the token, the registry DB
does not contain it). SecretProvider (#355) is the future hardening.

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

bot_bottle/orchestrator/client.py

@@ -90,14 +90,18 @@ class OrchestratorClient:
         image_ref: str = "",
         metadata: str = "",
         policy: str = "",
+        tokens: dict[str, str] | None = None,
     ) -> RegisteredBottle:
-        """Register a bottle and broker its launch (`POST /bottles`). Returns
-        its minted id + identity token."""
+        """Register a bottle and broker its launch (`POST /bottles`). `tokens`
+        are the per-bottle egress auth values (env_name -> value) the
+        orchestrator holds in memory for the gateway to inject. Returns the
+        minted id + identity token."""
         payload = self._ok("POST", "/bottles", {
             "source_ip": source_ip,
             "image_ref": image_ref,
             "metadata": metadata,
             "policy": policy,
+            "tokens": tokens or {},
         })
         bottle_id = payload.get("bottle_id")
         token = payload.get("identity_token")