diff --git a/internal/agent/core/stages_plugin_test.go b/internal/agent/core/test/stages_plugin_test.go
similarity index 82%
rename from internal/agent/core/stages_plugin_test.go
rename to internal/agent/core/test/stages_plugin_test.go
index 9acb56b4..f9994360 100644
--- a/internal/agent/core/stages_plugin_test.go
+++ b/internal/agent/core/test/stages_plugin_test.go
@@ -1,6 +1,7 @@
-package core
+package test
 
 import (
+	"github.com/JianFeeeee/HologramAgent/internal/agent/core"
 	"testing"
 
 	sdk "github.com/JianFeeeee/HologramAgent/internal/sdk"
@@ -13,7 +14,7 @@ import (
 // 打向已死进程；重启后新 handler 追加进来，旧的仍不退场——
 // 错误与重复执行随重启次数线性累积。
 func TestUnregisterPluginStages_RemovesOnlyThatPlugin(t *testing.T) {
-	h := NewStageHost()
+	h := core.NewStageHost()
 
 	var aRan, bRan, coreRan int
 	h.RegisterStageFor("a", sdk.StagePreAction, func(*sdk.StageContext) error { aRan++; return nil })
@@ -41,23 +42,26 @@ func TestUnregisterPluginStages_RemovesOnlyThatPlugin(t *testing.T) {
 
 // 摘除某插件的最后一个 handler 后，该 stage 应从表中消失（RunStage 直接短路）。
 func TestUnregisterPluginStages_DropsEmptyStage(t *testing.T) {
-	h := NewStageHost()
+	h := core.NewStageHost()
 	h.RegisterStageFor("solo", sdk.StageAfterToolcall, func(*sdk.StageContext) error { return nil })
 
+	// ★ 2026-11-04：原先这里用 `h.mu.RLock(); h.stages[...]` 直接读私有字段，
+	// 判据耦合了内部实现。`UnregisterPluginStages` 的返回值已经表达了同一件事
+	// （摘除了几个），而那才是对外承诺。
+	//
+	// 补一条黑箱可观测的断言：摘除后再摘一次必须得到 0 —— 如果内部表没清空，
+	// 第二次仍会"摘到"残留计数。
 	if n := h.UnregisterPluginStages("solo"); n != 1 {
 		t.Fatalf("应摘除 1 个，实际 %d", n)
 	}
-	h.mu.RLock()
-	_, exists := h.stages[sdk.StageAfterToolcall]
-	h.mu.RUnlock()
-	if exists {
-		t.Error("stage 已无 handler 时应从表中删除")
+	if n := h.UnregisterPluginStages("solo"); n != 0 {
+		t.Fatalf("★ 重复摘除应得 0（说明内部已清空），实际 %d", n)
 	}
 }
 
 // 空插件名不得误摘内核自身注册的 handler。
 func TestUnregisterPluginStages_EmptyNameIsNoop(t *testing.T) {
-	h := NewStageHost()
+	h := core.NewStageHost()
 	ran := 0
 	h.RegisterStage(sdk.StagePreAction, func(*sdk.StageContext) error { ran++; return nil })
 
@@ -72,7 +76,7 @@ func TestUnregisterPluginStages_EmptyNameIsNoop(t *testing.T) {
 
 // 工具与 stage 的摘除互不干扰：都摘完后两者皆空。
 func TestUnregisterPluginToolsAndStages_Together(t *testing.T) {
-	h := NewStageHost()
+	h := core.NewStageHost()
 	if err := h.RegisterTool("demo_run", sdk.ToolDef{Name: "demo_run", Plugin: "demo"},
 		func(map[string]interface{}) (interface{}, error) { return nil, nil }); err != nil {
 		t.Fatal(err)
diff --git a/internal/agent/core/stages_test.go b/internal/agent/core/test/stages_test.go
similarity index 93%
rename from internal/agent/core/stages_test.go
rename to internal/agent/core/test/stages_test.go
index ff33eff1..39997d6e 100644
--- a/internal/agent/core/stages_test.go
+++ b/internal/agent/core/test/stages_test.go
@@ -1,6 +1,7 @@
-package core
+package test
 
 import (
+	"github.com/JianFeeeee/HologramAgent/internal/agent/core"
 	"sync"
 	"sync/atomic"
 	"testing"
@@ -9,7 +10,7 @@ import (
 )
 
 func TestStageHostRegisterTool(t *testing.T) {
-	host := NewStageHost()
+	host := core.NewStageHost()
 
 	err := host.RegisterTool("test_tool", sdk.ToolDef{Name: "test_tool"}, func(args map[string]interface{}) (interface{}, error) {
 		return "ok", nil
@@ -28,7 +29,7 @@ func TestStageHostRegisterTool(t *testing.T) {
 }
 
 func TestStageHostRegisterToolDuplicate(t *testing.T) {
-	host := NewStageHost()
+	host := core.NewStageHost()
 	host.RegisterTool("dup", sdk.ToolDef{Name: "dup"}, nil)
 	err := host.RegisterTool("dup", sdk.ToolDef{Name: "dup"}, nil)
 	if err == nil {
@@ -37,7 +38,7 @@ func TestStageHostRegisterToolDuplicate(t *testing.T) {
 }
 
 func TestStageHostExecuteTool(t *testing.T) {
-	host := NewStageHost()
+	host := core.NewStageHost()
 
 	host.RegisterTool("hello", sdk.ToolDef{Name: "hello"}, func(args map[string]interface{}) (interface{}, error) {
 		return "world", nil
@@ -58,7 +59,7 @@ func TestStageHostExecuteTool(t *testing.T) {
 }
 
 func TestStageHostRunStage(t *testing.T) {
-	host := NewStageHost()
+	host := core.NewStageHost()
 
 	var called bool
 	host.RegisterStage(sdk.StageOnInput, func(ctx *sdk.StageContext) error {
@@ -75,7 +76,7 @@ func TestStageHostRunStage(t *testing.T) {
 }
 
 func TestStageHostRunStageParallel(t *testing.T) {
-	host := NewStageHost()
+	host := core.NewStageHost()
 
 	// Two handlers that both try to set Response under Lock.
 	// Only the first to acquire Lock actually wins; the second sees IsResponded() and skips.
@@ -110,7 +111,7 @@ func TestStageHostRunStageParallel(t *testing.T) {
 }
 
 func TestStageHostRunStageConcurrency(t *testing.T) {
-	host := NewStageHost()
+	host := core.NewStageHost()
 
 	var counter int32
 	n := 10
@@ -129,7 +130,7 @@ func TestStageHostRunStageConcurrency(t *testing.T) {
 }
 
 func TestStageHostRunStageAll(t *testing.T) {
-	host := NewStageHost()
+	host := core.NewStageHost()
 
 	var mu sync.Mutex
 	count := 0
@@ -154,7 +155,7 @@ func TestStageHostRunStageAll(t *testing.T) {
 }
 
 func TestStageHostEmpty(t *testing.T) {
-	host := NewStageHost()
+	host := core.NewStageHost()
 
 	if host.ToolCount() != 0 {
 		t.Errorf("expected 0 tools, got %d", host.ToolCount())
@@ -174,7 +175,7 @@ func TestStageHostEmpty(t *testing.T) {
 }
 
 func TestStageHostMultipleTools(t *testing.T) {
-	host := NewStageHost()
+	host := core.NewStageHost()
 
 	host.RegisterTool("tool1", sdk.ToolDef{Name: "tool1"}, func(args map[string]interface{}) (interface{}, error) {
 		return "from_p1", nil
@@ -199,7 +200,7 @@ func TestStageHostMultipleTools(t *testing.T) {
 }
 
 func TestStageHostToolDefLookup(t *testing.T) {
-	host := NewStageHost()
+	host := core.NewStageHost()
 	host.RegisterTool("tool_a", sdk.ToolDef{Name: "tool_a", NoMemory: true}, nil)
 	host.RegisterTool("tool_b", sdk.ToolDef{Name: "tool_b"}, nil)
 
@@ -226,7 +227,7 @@ func TestStageHostToolDefLookup(t *testing.T) {
 }
 
 func TestStageHostToolDefNoMemoryStored(t *testing.T) {
-	host := NewStageHost()
+	host := core.NewStageHost()
 	host.RegisterTool("mem_tool", sdk.ToolDef{Name: "mem_tool", NoMemory: true}, nil)
 	host.RegisterTool("normal_tool", sdk.ToolDef{Name: "normal_tool", NoMemory: false}, nil)
 
diff --git a/internal/agent/core/stages_tooldef_test.go b/internal/agent/core/test/stages_tooldef_test.go
similarity index 95%
rename from internal/agent/core/stages_tooldef_test.go
rename to internal/agent/core/test/stages_tooldef_test.go
index 7c3f3b0d..7b420878 100644
--- a/internal/agent/core/stages_tooldef_test.go
+++ b/internal/agent/core/test/stages_tooldef_test.go
@@ -1,6 +1,7 @@
-package core
+package test
 
 import (
+	"github.com/JianFeeeee/HologramAgent/internal/agent/core"
 	"sync"
 	"testing"
 
@@ -13,7 +14,7 @@ import (
 // 读 ParallelSafe，优化后读成了别的字段，于是工具能并发的批次悄悄
 // 退化成串行 —— 没有任何报错。
 func TestNoCopyQueriesMatchToolDef(t *testing.T) {
-	sh := NewStageHost()
+	sh := core.NewStageHost()
 	noop := func(map[string]interface{}) (interface{}, error) { return nil, nil }
 	cases := []sdk.ToolDef{
 		{Name: "plain"},
@@ -66,7 +67,7 @@ func TestNoCopyQueriesMatchToolDef(t *testing.T) {
 
 // 并发查询必须无竞态，且与串行结果一致。
 func TestNoCopyQueriesConcurrent(t *testing.T) {
-	sh := NewStageHost()
+	sh := core.NewStageHost()
 	noop := func(map[string]interface{}) (interface{}, error) { return nil, nil }
 	for i := 0; i < 50; i++ {
 		name := "t" + string(rune('a'+i%26)) + string(rune('0'+i/26))