fix(#353,#354): conditionally set generatedAgentConfigs based on agentMode

app/classroom/[id]/page.tsx

@@ -52,13 +52,13 @@ export default function ClassroomDetailPage() {
               });
               log.info('Loaded from server-side storage:', classroomId);
 
-              // Hydrate server-generated agents into IndexedDB + registry
+              // Hydrate server-generated agents into IndexedDB + registry.
+              // Don't set selectedAgentIds here — the general agent
+              // restoration logic below (Path 2) handles it uniformly.
               if (stage.generatedAgentConfigs?.length) {
                 const { saveGeneratedAgents } = await import('@/lib/orchestration/registry/store');
-                const { useSettingsStore } = await import('@/lib/store/settings');
-                const agentIds = await saveGeneratedAgents(stage.id, stage.generatedAgentConfigs);
-                useSettingsStore.getState().setSelectedAgentIds(agentIds);
-                log.info('Hydrated server-generated agents:', agentIds);
+                await saveGeneratedAgents(stage.id, stage.generatedAgentConfigs);
+                log.info('Hydrated server-generated agents for stage:', stage.id);
               }
             }
           }

lib/server/classroom-generation.ts

@@ -229,7 +229,7 @@ export async function generateClassroom(
 
   // Resolve agents based on agentMode
   let agents: AgentInfo[];
-  const agentMode = input.agentMode || 'default';
+  let agentMode = input.agentMode || 'default';
   if (agentMode === 'generate') {
     log.info('Generating custom agent profiles via LLM...');
     try {
@@ -238,6 +238,7 @@ export async function generateClassroom(
     } catch (e) {
       log.warn('Agent profile generation failed, falling back to defaults:', e);
       agents = getDefaultAgents();
+      agentMode = 'default';
     }
   } else {
     agents = getDefaultAgents();
@@ -328,17 +329,24 @@ export async function generateClassroom(
     style: 'interactive',
     createdAt: Date.now(),
     updatedAt: Date.now(),
-    // Embed agent configs so API-generated classrooms can hydrate
-    // the client-side agent registry without IndexedDB
-    generatedAgentConfigs: agents.map((a, i) => ({
-      id: a.id,
-      name: a.name,
-      role: a.role,
-      persona: a.persona || '',
-      avatar: AGENT_DEFAULT_AVATARS[i % AGENT_DEFAULT_AVATARS.length],
-      color: AGENT_COLOR_PALETTE[i % AGENT_COLOR_PALETTE.length],
-      priority: a.role === 'teacher' ? 10 : a.role === 'assistant' ? 7 : 5,
-    })),
+    // For LLM-generated agents, embed full configs so the client can
+    // hydrate the agent registry without prior IndexedDB data.
+    // For default agents, just record IDs — the client already has them.
+    ...(agentMode === 'generate'
+      ? {
+          generatedAgentConfigs: agents.map((a, i) => ({
+            id: a.id,
+            name: a.name,
+            role: a.role,
+            persona: a.persona || '',
+            avatar: AGENT_DEFAULT_AVATARS[i % AGENT_DEFAULT_AVATARS.length],
+            color: AGENT_COLOR_PALETTE[i % AGENT_COLOR_PALETTE.length],
+            priority: a.role === 'teacher' ? 10 : a.role === 'assistant' ? 7 : 5,
+          })),
+        }
+      : {
+          agentIds: agents.map((a) => a.id),
+        }),
   };
 
   const store = createInMemoryStore(stage);

tests/server/classroom-agent-mode.test.ts

@@ -0,0 +1,115 @@
+import { describe, test, expect } from 'vitest';
+/**
+ * Unit test for #353 fix: verify Stage object has correct agent fields
+ * based on agentMode.
+ *
+ * This doesn't call any LLM — it directly tests the conditional logic
+ * that was changed in classroom-generation.ts.
+ */
+
+import { getDefaultAgents } from '@/lib/orchestration/registry/store';
+import { AGENT_COLOR_PALETTE, AGENT_DEFAULT_AVATARS } from '@/lib/constants/agent-defaults';
+
+interface DefaultModeFields {
+  agentIds: string[];
+}
+
+interface GenerateModeFields {
+  generatedAgentConfigs: Array<{
+    id: string;
+    name: string;
+    role: string;
+    persona: string;
+    avatar: string;
+    color: string;
+    priority: number;
+  }>;
+}
+
+describe('#353: generatedAgentConfigs conditional on agentMode', () => {
+  // Replicate the Stage construction logic from classroom-generation.ts L322-349
+  function buildStageAgentFields(
+    agentMode: 'default' | 'generate',
+    agents: Array<{ id: string; name: string; role: string; persona?: string }>,
+  ): DefaultModeFields | GenerateModeFields {
+    return agentMode === 'generate'
+      ? {
+          generatedAgentConfigs: agents.map((a, i) => ({
+            id: a.id,
+            name: a.name,
+            role: a.role,
+            persona: a.persona || '',
+            avatar: AGENT_DEFAULT_AVATARS[i % AGENT_DEFAULT_AVATARS.length],
+            color: AGENT_COLOR_PALETTE[i % AGENT_COLOR_PALETTE.length],
+            priority: a.role === 'teacher' ? 10 : a.role === 'assistant' ? 7 : 5,
+          })),
+        }
+      : {
+          agentIds: agents.map((a) => a.id),
+        };
+  }
+
+  test('default mode should set agentIds, NOT generatedAgentConfigs', () => {
+    const agents = getDefaultAgents();
+    const fields = buildStageAgentFields('default', agents);
+
+    // Should have agentIds
+    expect(fields).toHaveProperty('agentIds');
+    expect((fields as DefaultModeFields).agentIds).toEqual([
+      'default-1',
+      'default-2',
+      'default-3',
+      'default-4',
+      'default-5',
+      'default-6',
+    ]);
+
+    // Should NOT have generatedAgentConfigs
+    expect(fields).not.toHaveProperty('generatedAgentConfigs');
+  });
+
+  test('generate mode should set generatedAgentConfigs, NOT agentIds', () => {
+    const agents = [
+      { id: 'gen-server-0', name: 'Prof. Li', role: 'teacher', persona: 'An expert' },
+      { id: 'gen-server-1', name: 'Assistant', role: 'assistant', persona: 'Helpful' },
+      { id: 'gen-server-2', name: 'Student', role: 'student', persona: 'Curious' },
+    ];
+    const fields = buildStageAgentFields('generate', agents);
+
+    // Should have generatedAgentConfigs
+    expect(fields).toHaveProperty('generatedAgentConfigs');
+    expect((fields as GenerateModeFields).generatedAgentConfigs).toHaveLength(3);
+    expect((fields as GenerateModeFields).generatedAgentConfigs[0].id).toBe('gen-server-0');
+
+    // Should NOT have agentIds
+    expect(fields).not.toHaveProperty('agentIds');
+  });
+
+  test('generate mode with LLM fallback should behave like default mode', () => {
+    // Simulates: agentMode was 'generate', LLM failed, fell back to defaults
+    // After our fix, agentMode is reset to 'default' in the catch block
+    let agentMode: 'default' | 'generate' = 'generate';
+    let agents;
+
+    try {
+      throw new Error('Simulated LLM failure');
+    } catch {
+      agents = getDefaultAgents();
+      agentMode = 'default'; // ← This is our fix
+    }
+
+    const fields = buildStageAgentFields(agentMode, agents);
+
+    // Should behave exactly like default mode
+    expect(fields).toHaveProperty('agentIds');
+    expect(fields).not.toHaveProperty('generatedAgentConfigs');
+    expect((fields as DefaultModeFields).agentIds).toEqual([
+      'default-1',
+      'default-2',
+      'default-3',
+      'default-4',
+      'default-5',
+      'default-6',
+    ]);
+  });
+});