feat: AutoZero 通用 Agent 框架（从 AutoGo 五阶段拆分完成）

llm（三协议 Provider）/ session（JSONL 持久化）/ tools（Registry、围栏、
builtin、computer）/ cdp（browser）/ skills / mcp / agent（循环、两级压缩、
编排、审批门控）+ 底座 jsonl/textx/execx/diag/scratch/spill/imagecache。

产品装配代码（config 桥接、schedule 工具、memory/plan/retro/prompt）
留在 AutoGo，宿主接入方式见 MIGRATION.md。

imagecache/cache_test.go

@@ -0,0 +1,188 @@
+package imagecache
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+)
+
+func TestCache_StoreAndLoad(t *testing.T) {
+	dir := t.TempDir()
+	cache, err := New(dir, 0, 0)
+	if err != nil {
+		t.Fatalf("New() error = %v", err)
+	}
+
+	// 存储图片
+	data := []byte("fake image data")
+	filename, err := cache.Store(data, ".jpg")
+	if err != nil {
+		t.Fatalf("Store() error = %v", err)
+	}
+
+	// 验证文件存在
+	path := filepath.Join(dir, filename)
+	if _, err := os.Stat(path); os.IsNotExist(err) {
+		t.Errorf("Store() file not created: %s", path)
+	}
+
+	// 加载图片
+	loaded, err := cache.Load(filename)
+	if err != nil {
+		t.Fatalf("Load() error = %v", err)
+	}
+
+	if string(loaded) != string(data) {
+		t.Errorf("Load() = %s, want %s", loaded, data)
+	}
+}
+
+func TestCache_LoadBase64(t *testing.T) {
+	dir := t.TempDir()
+	cache, err := New(dir, 0, 0)
+	if err != nil {
+		t.Fatalf("New() error = %v", err)
+	}
+
+	data := []byte("test data")
+	filename, err := cache.Store(data, ".png")
+	if err != nil {
+		t.Fatalf("Store() error = %v", err)
+	}
+
+	b64, err := cache.LoadBase64(filename)
+	if err != nil {
+		t.Fatalf("LoadBase64() error = %v", err)
+	}
+
+	if b64 == "" {
+		t.Error("LoadBase64() returned empty string")
+	}
+}
+
+func TestCache_Exists(t *testing.T) {
+	dir := t.TempDir()
+	cache, err := New(dir, 0, 0)
+	if err != nil {
+		t.Fatalf("New() error = %v", err)
+	}
+
+	filename, _ := cache.Store([]byte("data"), ".jpg")
+
+	if !cache.Exists(filename) {
+		t.Error("Exists() = false, want true")
+	}
+
+	if cache.Exists("nonexistent.jpg") {
+		t.Error("Exists() = true for nonexistent file")
+	}
+}
+
+func TestCache_Delete(t *testing.T) {
+	dir := t.TempDir()
+	cache, err := New(dir, 0, 0)
+	if err != nil {
+		t.Fatalf("New() error = %v", err)
+	}
+
+	filename, _ := cache.Store([]byte("data"), ".jpg")
+
+	if err := cache.Delete(filename); err != nil {
+		t.Fatalf("Delete() error = %v", err)
+	}
+
+	if cache.Exists(filename) {
+		t.Error("Delete() file still exists")
+	}
+}
+
+func TestCache_List(t *testing.T) {
+	dir := t.TempDir()
+	cache, err := New(dir, 0, 0)
+	if err != nil {
+		t.Fatalf("New() error = %v", err)
+	}
+
+	cache.Store([]byte("data1"), ".jpg")
+	cache.Store([]byte("data2"), ".png")
+
+	files, err := cache.List()
+	if err != nil {
+		t.Fatalf("List() error = %v", err)
+	}
+
+	if len(files) != 2 {
+		t.Errorf("List() returned %d files, want 2", len(files))
+	}
+}
+
+func TestCache_Stats(t *testing.T) {
+	dir := t.TempDir()
+	cache, err := New(dir, 0, 0)
+	if err != nil {
+		t.Fatalf("New() error = %v", err)
+	}
+
+	cache.Store([]byte("data1"), ".jpg")
+	cache.Store([]byte("data2"), ".png")
+
+	count, totalSize, err := cache.Stats()
+	if err != nil {
+		t.Fatalf("Stats() error = %v", err)
+	}
+
+	if count != 2 {
+		t.Errorf("Stats() count = %d, want 2", count)
+	}
+
+	if totalSize <= 0 {
+		t.Errorf("Stats() totalSize = %d, want > 0", totalSize)
+	}
+}
+
+func TestCache_SafePath(t *testing.T) {
+	dir := t.TempDir()
+	cache, err := New(dir, 0, 0)
+	if err != nil {
+		t.Fatalf("New() error = %v", err)
+	}
+
+	// 测试路径遍历防护
+	tests := []struct {
+		input    string
+		expected string
+	}{
+		{"test.jpg", filepath.Join(dir, "test.jpg")},
+		{"../etc/passwd", filepath.Join(dir, "passwd")},
+		{"/etc/passwd", filepath.Join(dir, "passwd")},
+		{"subdir/test.jpg", filepath.Join(dir, "test.jpg")},
+	}
+
+	for _, tt := range tests {
+		got := cache.safePath(tt.input)
+		if got != tt.expected {
+			t.Errorf("safePath(%q) = %q, want %q", tt.input, got, tt.expected)
+		}
+	}
+}
+
+func TestDetectMIME(t *testing.T) {
+	tests := []struct {
+		filename string
+		expected string
+	}{
+		{"test.jpg", "image/jpeg"},
+		{"test.jpeg", "image/jpeg"},
+		{"test.png", "image/png"},
+		{"test.gif", "image/gif"},
+		{"test.webp", "image/webp"},
+		{"test.unknown", "image/jpeg"},
+	}
+
+	for _, tt := range tests {
+		got := detectMIME(tt.filename)
+		if got != tt.expected {
+			t.Errorf("detectMIME(%q) = %q, want %q", tt.filename, got, tt.expected)
+		}
+	}
+}