fix(orchestrator): give pr_reviewer a spawn manifest so it can claim work

pr_reviewer was absent from GATEWAY_ENABLED_ROLES, so the spawn mounted no
tool-manifest and set ROBOCO_GATEWAY_ENABLED=false. The reviewer booted with
no flow verbs, could never claim its external-PR task, exited, and was
respawned on the same task every tick — an endless loop that burned tokens.

Add pr_reviewer to the set, plus a regression invariant asserting every
spawnable seeded role has a manifest (only the never-spawned roles —
prompter/secretary/ceo/system — may be absent) and a direct pr-reviewer-1
manifest test checking its claim_pr_review/post_pr_review verbs are present.

roboco/runtime/orchestrator.py

@@ -323,7 +323,12 @@ def _resolve_project_slug_from_git_context(
 # SPAWN MANIFEST — per-developer tool manifest mounting (Phase 1)
 # =============================================================================
 
-# Phase 4: every role gets a gateway manifest. The legacy briefing path is gone.
+# Phase 4: every spawned role gets a gateway manifest. The legacy briefing path
+# is gone. A role omitted here gets NO manifest and ROBOCO_GATEWAY_ENABLED=false,
+# i.e. none of its flow verbs are pre-registered — so it can never claim its work
+# and the dispatcher respawns it on the same task forever. The only roles that
+# may be absent are the human-only ones (prompter, secretary) that the
+# orchestrator never spawns as delivery agents.
 GATEWAY_ENABLED_ROLES: frozenset[str] = frozenset(
     {
         "developer",
@@ -334,6 +339,7 @@ GATEWAY_ENABLED_ROLES: frozenset[str] = frozenset(
         "product_owner",
         "head_marketing",
         "auditor",
+        "pr_reviewer",
     }
 )
 

tests/unit/runtime/test_orchestrator_manifest.py

@@ -6,12 +6,19 @@ import json
 from typing import TYPE_CHECKING
 from unittest.mock import patch
 
+from roboco.agents_config import ALL_AGENTS, get_agent_role
 from roboco.runtime.orchestrator import GATEWAY_ENABLED_ROLES, _build_manifest_for_agent
 from roboco.seeds.initial_data import AGENT_UUIDS
 
 if TYPE_CHECKING:
     from pathlib import Path
 
+# Roles the orchestrator never spawns as containerized delivery agents, so they
+# legitimately get no spawn manifest: the human-only chat agents (prompter,
+# secretary), the human CEO, and the orchestrator's own `system` sentinel. Every
+# OTHER seeded role must be gateway-enabled or it boots with no flow verbs.
+NON_SPAWNED_ROLES = {"prompter", "secretary", "ceo", "system"}
+
 
 class TestGatewayEnabledRoles:
     def test_all_roles_enabled(self) -> None:
@@ -28,6 +35,34 @@ class TestGatewayEnabledRoles:
         assert "head_marketing" in GATEWAY_ENABLED_ROLES
         assert "auditor" in GATEWAY_ENABLED_ROLES
 
+    def test_pr_reviewer_enabled(self) -> None:
+        """The PR reviewer is a spawned delivery agent — it must be enabled.
+
+        Without this it gets ROBOCO_GATEWAY_ENABLED=false and no manifest, so
+        none of its flow verbs (claim_pr_review/post_pr_review) are registered;
+        it can never claim its task and the dispatcher respawns it forever.
+        """
+        assert "pr_reviewer" in GATEWAY_ENABLED_ROLES
+
+    def test_every_spawnable_agent_role_is_gateway_enabled(self) -> None:
+        """Invariant: every seeded agent the orchestrator spawns has a manifest.
+
+        Guards against the regression where a new spawnable role is added to the
+        roster but forgotten here — that role would spawn with no flow verbs and
+        loop. Only the never-spawned roles (prompter/secretary/ceo/system) may be
+        absent.
+        """
+        missing = {
+            agent_id: role
+            for agent_id in ALL_AGENTS
+            if (role := get_agent_role(agent_id)) not in NON_SPAWNED_ROLES
+            and role not in GATEWAY_ENABLED_ROLES
+        }
+        assert not missing, (
+            f"spawnable agents missing from GATEWAY_ENABLED_ROLES "
+            f"(would loop with no flow verbs): {missing}"
+        )
+
 
 class TestBuildManifestForAgent:
     def test_developer_writes_file(self, tmp_path: Path) -> None:
@@ -152,6 +187,26 @@ class TestBuildManifestForAgent:
         data = json.loads(result.read_text())
         assert data["role"] == "main_pm"
 
+    def test_pr_reviewer_writes_file_with_review_verbs(self, tmp_path: Path) -> None:
+        """pr-reviewer-1 produces a manifest carrying its review flow verbs.
+
+        Regression guard for the respawn loop: if this returns None (role not
+        gateway-enabled) the reviewer spawns with no task tools.
+        """
+        with patch("roboco.runtime.orchestrator.settings") as mock_settings:
+            mock_settings.manifest_host_dir = str(tmp_path)
+            mock_settings.workspaces_root = str(tmp_path / "workspaces")
+
+            result = _build_manifest_for_agent("pr-reviewer-1", "claude-sonnet-4-6")
+
+        assert result is not None, "pr-reviewer-1 must produce a manifest"
+        assert result.exists()
+        assert result.name == "pr-reviewer-1.json"
+        data = json.loads(result.read_text())
+        assert data["role"] == "pr_reviewer"
+        assert "claim_pr_review" in data["flow_tools"]
+        assert "post_pr_review" in data["flow_tools"]
+
     def test_manifest_dir_created_if_absent(self, tmp_path: Path) -> None:
         """manifest_host_dir is created automatically when it doesn't exist."""
         nested = tmp_path / "new" / "nested" / "dir"