feat(manifest): add agent_provider.auth_token for Claude OAuth via egress

Operators can now declare:

  agent_provider:
    template: claude
    auth_token: BOT_BOTTLE_CLAUDE_OAUTH_TOKEN

and the provisioner injects a provider-owned api.anthropic.com egress
route (Bearer, tls_passthrough) rather than requiring a manually
declared route with the former claude_code_oauth role.

Changes:
- Add auth_token field to AgentProvider; validate claude-only.
- Remove claude_code_oauth from EGRESS_ROLES / PROVIDER_EGRESS_ROLES.
  Manifests that declare the role now fail at parse time with "unknown
  role" — the provisioner owns the route.
- agent_provision_plan: replace manifest_egress_routes/has_provider_auth
  with auth_token; Claude branch injects the api.anthropic.com route,
  placeholder env, and nonessential-traffic flags when auth_token is set.
- Add hidden_env_names: frozenset[str] to AgentProvisionPlan; Claude
  branch populates it with CLAUDE_CODE_OAUTH_TOKEN.
- Remove auth_role from AgentProviderRuntime and placeholder_env_for().
- print_util.visible_agent_env_names: accept hidden_env_names from the
  plan instead of dispatching on agent_provider_template.
- Both backends: drop manifest_egress_routes call, pass auth_token.
- PRD 0029 rescoped to cover both Codex and Claude provider auth.

Assisted-by: Claude Code

bot_bottle/backend/docker/bottle_plan.py

@@ -89,7 +89,7 @@ class DockerBottlePlan(BottlePlan):
                 | set(self.forwarded_env.keys())
                 | set(self.agent_provision.guest_env.keys())
             ),
-            agent_provider_template=self.agent_provider_template,
+            hidden_env_names=self.agent_provision.hidden_env_names,
         )
 
         print(file=sys.stderr)