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。

agent/skill_test.go

@@ -0,0 +1,67 @@
+package agent
+
+import (
+	"context"
+	"strings"
+	"testing"
+
+	"git.gopher.ink/mirrors2/AutoZero/llm"
+	"git.gopher.ink/mirrors2/AutoZero/skills"
+)
+
+// TestLoadSkillTool：load_skill 返回正文；allowed-tools 白名单过滤生效，
+// 白名单外工具被拒。
+func TestLoadSkillTool(t *testing.T) {
+	prov := &scriptedProvider{fn: func(call int, _ string, _ []llm.Message, tools []llm.ToolDef) (llm.Message, error) {
+		switch call {
+		case 1: // 模型加载 skill（工具全量可见）
+			if !hasName(tools, "grep") || !hasName(tools, "load_skill") {
+				t.Errorf("call 1: expected full toolset, got %v", toolNames(tools))
+			}
+			return llm.Message{Role: llm.RoleAssistant, ToolCalls: []llm.ToolCall{
+				{ID: "sk1", Name: "load_skill", Input: `{"name":"review"}`},
+			}}, nil
+		case 2: // 白名单生效：只剩 load_skill + read
+			if hasName(tools, "grep") || !hasName(tools, "read") || !hasName(tools, "load_skill") {
+				t.Errorf("call 2: expected filtered toolset [load_skill read], got %v", toolNames(tools))
+			}
+			return llm.Message{Role: llm.RoleAssistant, ToolCalls: []llm.ToolCall{
+				{ID: "t1", Name: "grep", Input: `{"pattern":"x"}`}, // 白名单外 → 应得到错误结果
+			}}, nil
+		case 3:
+			return llm.Message{Role: llm.RoleAssistant, Content: "done"}, nil
+		}
+		t.Errorf("unexpected call %d", call)
+		return llm.Message{}, nil
+	}}
+
+	a, sess := newTestAgent(t)
+	a.Provider = prov
+	a.Skills = []skills.Skill{{
+		Name:         "review",
+		Description:  "code review",
+		AllowedTools: []string{"read"},
+		Body:         "Read the diff and comment.",
+	}}
+	if err := a.Tools.Register(a.SkillTool()); err != nil {
+		t.Fatal(err)
+	}
+	if err := a.Run(context.Background(), "review the code"); err != nil {
+		t.Fatal(err)
+	}
+
+	// skill 正文作为工具结果回填
+	var gotBody bool
+	for _, m := range sess.Messages {
+		if m.Role == llm.RoleTool && strings.Contains(m.Content, "Read the diff") {
+			gotBody = true
+		}
+		// grep 调用应被白名单拒绝
+		if m.ToolCallID == "t1" && !strings.Contains(m.Content, "not allowed") {
+			t.Fatalf("grep should be denied by skill filter, got %q", m.Content)
+		}
+	}
+	if !gotBody {
+		t.Fatal("skill body not fed back as tool result")
+	}
+}