Tighten subagent prompt file workflow

pkg/tools/subagent_config_manager.go

@@ -49,11 +49,18 @@ func UpsertConfigSubagent(configPath string, args map[string]interface{}) (map[s
 	if err != nil {
 		return nil, err
 	}
+	mainID := strings.TrimSpace(cfg.Agents.Router.MainAgentID)
+	if mainID == "" {
+		mainID = "main"
+	}
 	if cfg.Agents.Subagents == nil {
 		cfg.Agents.Subagents = map[string]config.SubagentConfig{}
 	}
 	subcfg := cfg.Agents.Subagents[agentID]
 	if enabled, ok := boolArgFromMap(args, "enabled"); ok {
+		if agentID == mainID && !enabled {
+			return nil, fmt.Errorf("main agent %q cannot be disabled", agentID)
+		}
 		subcfg.Enabled = enabled
 	} else if !subcfg.Enabled {
 		subcfg.Enabled = true
@@ -84,6 +91,9 @@ func UpsertConfigSubagent(configPath string, args map[string]interface{}) (map[s
 	} else if strings.TrimSpace(subcfg.Type) == "" {
 		subcfg.Type = "worker"
 	}
+	if subcfg.Enabled && strings.TrimSpace(subcfg.SystemPromptFile) == "" {
+		return nil, fmt.Errorf("system_prompt_file is required for enabled agent %q", agentID)
+	}
 	cfg.Agents.Subagents[agentID] = subcfg
 	if kws := stringListArgFromMap(args, "routing_keywords"); len(kws) > 0 {
 		cfg.Agents.Router.Rules = upsertRouteRuleConfig(cfg.Agents.Router.Rules, config.AgentRouteRule{
@@ -123,6 +133,13 @@ func DeleteConfigSubagent(configPath, agentID string) (map[string]interface{}, e
 	if err != nil {
 		return nil, err
 	}
+	mainID := strings.TrimSpace(cfg.Agents.Router.MainAgentID)
+	if mainID == "" {
+		mainID = "main"
+	}
+	if agentID == mainID {
+		return nil, fmt.Errorf("main agent %q cannot be deleted", agentID)
+	}
 	if cfg.Agents.Subagents == nil {
 		return map[string]interface{}{"ok": false, "found": false, "agent_id": agentID}, nil
 	}

pkg/tools/subagent_config_tool_test.go

@@ -38,9 +38,10 @@ func TestSubagentConfigToolUpsert(t *testing.T) {
 	cfg := config.DefaultConfig()
 	cfg.Agents.Router.Enabled = true
 	cfg.Agents.Subagents["main"] = config.SubagentConfig{
-		Enabled: true,
-		Type:    "router",
-		Role:    "orchestrator",
+		Enabled:          true,
+		Type:             "router",
+		Role:             "orchestrator",
+		SystemPromptFile: "agents/main/AGENT.md",
 	}
 	if err := config.SaveConfig(configPath, cfg); err != nil {
 		t.Fatalf("save config failed: %v", err)
@@ -50,14 +51,15 @@ func TestSubagentConfigToolUpsert(t *testing.T) {
 
 	tool := NewSubagentConfigTool(configPath)
 	out, err := tool.Execute(context.Background(), map[string]interface{}{
-		"action":           "upsert",
-		"agent_id":         "reviewer",
-		"role":             "testing",
-		"display_name":     "Review Agent",
-		"description":      "负责回归与评审",
-		"system_prompt":    "review changes",
-		"routing_keywords": []interface{}{"review", "regression"},
-		"tool_allowlist":   []interface{}{"shell", "sessions"},
+		"action":             "upsert",
+		"agent_id":           "reviewer",
+		"role":               "testing",
+		"display_name":       "Review Agent",
+		"description":        "负责回归与评审",
+		"system_prompt":      "review changes",
+		"system_prompt_file": "agents/reviewer/AGENT.md",
+		"routing_keywords":   []interface{}{"review", "regression"},
+		"tool_allowlist":     []interface{}{"shell", "sessions"},
 	})
 	if err != nil {
 		t.Fatalf("upsert failed: %v", err)

pkg/tools/subagent_profile_test.go

@@ -171,8 +171,9 @@ func TestSubagentProfileStoreRejectsWritesForConfigManagedProfiles(t *testing.T)
 
 	cfg := config.DefaultConfig()
 	cfg.Agents.Subagents["tester"] = config.SubagentConfig{
-		Enabled: true,
-		Role:    "test",
+		Enabled:          true,
+		Role:             "test",
+		SystemPromptFile: "agents/tester/AGENT.md",
 	}
 	runtimecfg.Set(cfg)