Wire GenAI telemetry: settings surface, service name, and agent names (N3 WP4)

Why: spans now follow the OTel GenAI convention (Agent-Native#32); the
product needs the settings surface for the exporter, a meaningful
service.name, and per-profile agent names.
Evidence: go test -count=1 ./... green; TestTelemetryFlagsDefaults
(otlpEndpoint registered default empty = no export, serviceName
default agent-system-backend); nested pins carry the convention work.
Impact: nothing is exported unless telemetry.otlpEndpoint (or the env
var) is set; agent spans are named by profile id.
Refs: Agent-Native#32, Agent-Squad#36, N3 plan WP4

internal/app/app.go

@@ -84,7 +84,6 @@ func Run(opt Options) error {
 	if opt.InsecureListen && !config.IsLoopbackListen(opt.Addr) && !resolved.AuthEnabled() {
 		log.Printf("warning: listening on %s without authentication because insecureListen is set", opt.Addr)
 	}
-	traceFn := telemetry.StartFunc(logger)
 	var st *store.Store
 	var err error
 	if opt.StorageDSN != "" {
@@ -124,6 +123,10 @@ func Run(opt Options) error {
 		return fmt.Errorf("code orchestration tool: %w", err)
 	}
 	setSvc := settings.NewService(st)
+	effBoot := setSvc.Effective(store.OwnerDefault, "")
+	traceFn := telemetry.StartFunc(logger,
+		telemetry.WithServiceName(effBoot.GetString("telemetry.serviceName", "agent-system-backend")),
+		telemetry.WithEndpoint(effBoot.GetString("telemetry.otlpEndpoint", "")))
 	setSvc.SetSystemOverride(map[string]any{"storage": map[string]any{"dataDir": opt.DataDir}})
 	// 点路径键展开必须在读 tools.tavily.apiKeys 之前，否则启动仍注册旧池。
 	norm, err := setSvc.NormalizeStored()

internal/app/intent_flags_test.go

@@ -27,3 +27,18 @@ func TestIntentSlowLaneFlagsDefaultOff(t *testing.T) {
 		}
 	}
 }
+
+// 遥测开关默认安全（N3 WP4）：otlpEndpoint 默认空（不导出，保持现状），
+// serviceName 有非空默认。两处都注册进 Schema。
+func TestTelemetryFlagsDefaults(t *testing.T) {
+	seen := map[string]core.SettingDesc{}
+	for _, d := range settings.Schema() {
+		seen[d.Key] = d
+	}
+	if d, ok := seen["telemetry.otlpEndpoint"]; !ok || d.Default != "" {
+		t.Fatalf("otlpEndpoint 必须注册且默认空：%+v", d)
+	}
+	if d, ok := seen["telemetry.serviceName"]; !ok || d.Default != "agent-system-backend" {
+		t.Fatalf("serviceName 必须注册且默认 agent-system-backend：%+v", d)
+	}
+}

internal/runtime/llm.go

@@ -399,6 +399,14 @@ func outputTokenCap(budget core.RunBudget, eff core.EffectiveSettings, key strin
 	return 0
 }
 
+// agentNameOf 是 OTel gen_ai.agent.name 的取值（画像 ID，空回退 agent-system）。
+func agentNameOf(prof core.AgentProfile) string {
+	if strings.TrimSpace(prof.ID) != "" {
+		return prof.ID
+	}
+	return "agent-system"
+}
+
 // openLLMClient 不设 HTTP 客户端超时。单次生成可能很长，停止按钮通过 run 的 context 取消。
 func openLLMClient(base, key string) *agentllm.Client {
 	return &agentllm.Client{BaseURL: base, APIKey: key, HTTPClient: &http.Client{}}

internal/runtime/llm_direct.go

@@ -204,6 +204,7 @@ func (l *LLMRunner) runDirect(rc RunCtx, stream agentllm.StreamFunc, model strin
 		Reminders:              st.reminders,
 		PermissionAsk:          PermissionAskOf(rc),
 		Trace:                  l.Trace,
+		AgentName:              agentNameOf(rc.Profile()),
 		UnknownTool: func(call agentllm.ToolCall) agenttools.Result {
 			return st.runTool(call.Name, call.Arguments)
 		},

internal/runtime/sub_loop.go

@@ -110,6 +110,7 @@ func (l *SubLLMRunner) Execute(rc RunCtx) error {
 		OnEvent:                st.onEvent,
 		PermissionAsk:          PermissionAskOf(rc),
 		Trace:                  l.Trace,
+		AgentName:              agentNameOf(rc.Profile()),
 	}, user)
 	if len(st.parts) == 0 {
 		st.parts = append(st.parts, core.Part{Type: core.PartText, Text: "（子代理未返回内容）"})

internal/settings/settings.go

@@ -96,6 +96,8 @@ func Schema() []core.SettingDesc {
 		{Key: "runtime.composeFinal", Group: "runtime", Label: "终轮整理回复", Type: core.SettingBool, Default: true, Effect: core.EffectNewRun, Description: "用过工具的回合结束后，再用主模型写一段直接回答用户的最终回复"},
 		{Key: "runtime.intentSemantic", Group: "runtime", Label: "意图语义裁决（慢通道）", Type: core.SettingBool, Default: false, Effect: core.EffectRestart, Description: "规则歧义时用 embedding 语义相似度裁决。需已配置 embedding 端点。默认关闭（行为与 I1 一致）"},
 		{Key: "runtime.intentGenerator", Group: "runtime", Label: "意图命令生成（慢通道）", Type: core.SettingBool, Default: false, Effect: core.EffectRestart, Description: "规则与语义都未命中时用轻量模型生成意图命令（幻觉 fail-closed 回退）。默认关闭（行为与 I1 一致）"},
+		{Key: "telemetry.otlpEndpoint", Group: "telemetry", Label: "OTLP 端点", Type: core.SettingString, Default: "", Effect: core.EffectRestart, Description: "OTel HTTP JSON 上报端点（如 http://localhost:4318）。空 = 不导出（默认）；环境变量 OTEL_EXPORTER_OTLP_ENDPOINT 作为后备"},
+		{Key: "telemetry.serviceName", Group: "telemetry", Label: "遥测 service.name", Type: core.SettingString, Default: "agent-system-backend", Effect: core.EffectRestart, Description: "OTLP resource 的 service.name"},
 		{Key: "context.maxHistoryMessages", Group: "context", Label: "历史窗口条数", Type: core.SettingNumber, Default: 40, Effect: core.EffectNewRun},
 		{Key: "context.maxToolResultChars", Group: "context", Label: "工具结果上限（字符）", Type: core.SettingNumber, Default: 20000, Effect: core.EffectNewRun},
 		{Key: "context.userInstructions", Group: "context", Label: "个人指令", Type: core.SettingString, Default: "", Effect: core.EffectNewRun, Description: "每次对话附在上下文末尾，不改系统前缀"},