refactor: add role agent plan ssot

src/role-agent-plan.test.ts

@@ -0,0 +1,63 @@
+import { describe, expect, it } from 'vitest';
+
+import { resolveRoleAgentPlan } from './role-agent-plan.js';
+
+describe('resolveRoleAgentPlan', () => {
+  it('uses the group agent type as owner in single rooms', () => {
+    expect(
+      resolveRoleAgentPlan({
+        paired: false,
+        groupAgentType: 'codex',
+        configuredReviewer: 'claude-code',
+        configuredArbiter: 'claude-code',
+      }),
+    ).toEqual({
+      ownerAgentType: 'codex',
+      reviewerAgentType: null,
+      arbiterAgentType: null,
+    });
+  });
+
+  it('falls back to claude-code when group agent type is undefined', () => {
+    expect(
+      resolveRoleAgentPlan({
+        paired: false,
+        groupAgentType: undefined,
+        configuredReviewer: 'codex',
+      }),
+    ).toEqual({
+      ownerAgentType: 'claude-code',
+      reviewerAgentType: null,
+      arbiterAgentType: null,
+    });
+  });
+
+  it('uses configured reviewer and arbiter when paired room roles differ', () => {
+    expect(
+      resolveRoleAgentPlan({
+        paired: true,
+        groupAgentType: 'codex',
+        configuredReviewer: 'claude-code',
+        configuredArbiter: 'claude-code',
+      }),
+    ).toEqual({
+      ownerAgentType: 'codex',
+      reviewerAgentType: 'claude-code',
+      arbiterAgentType: 'claude-code',
+    });
+  });
+
+  it('collapses reviewer to owner and keeps arbiter null when absent', () => {
+    expect(
+      resolveRoleAgentPlan({
+        paired: true,
+        groupAgentType: 'claude-code',
+        configuredReviewer: 'claude-code',
+      }),
+    ).toEqual({
+      ownerAgentType: 'claude-code',
+      reviewerAgentType: 'claude-code',
+      arbiterAgentType: null,
+    });
+  });
+});

src/role-agent-plan.ts

@@ -0,0 +1,41 @@
+import type { AgentType } from './types.js';
+
+export interface RoleAgentPlan {
+  ownerAgentType: AgentType;
+  reviewerAgentType: AgentType | null;
+  arbiterAgentType: AgentType | null;
+}
+
+export interface ResolveRoleAgentPlanArgs {
+  paired: boolean;
+  groupAgentType?: AgentType;
+  configuredReviewer: AgentType;
+  configuredArbiter?: AgentType | null;
+}
+
+/**
+ * Preserve current runtime agent-resolution behavior in one pure helper.
+ * This intentionally mirrors today's paired inference and does not read room mode yet.
+ */
+export function resolveRoleAgentPlan(
+  args: ResolveRoleAgentPlanArgs,
+): RoleAgentPlan {
+  const ownerAgentType: AgentType = args.groupAgentType || 'claude-code';
+
+  if (!args.paired) {
+    return {
+      ownerAgentType,
+      reviewerAgentType: null,
+      arbiterAgentType: null,
+    };
+  }
+
+  return {
+    ownerAgentType,
+    reviewerAgentType:
+      args.configuredReviewer !== ownerAgentType
+        ? args.configuredReviewer
+        : ownerAgentType,
+    arbiterAgentType: args.configuredArbiter ?? null,
+  };
+}