feat(goals): 目标设定 agent 提取并登记测试资产范围

- DecomposeGoals 新增 as/taskID 参数，有效时复用 add_task_scope 工具挂入本次调用
- 追加 code-owned tail(仅工具挂上时)：从目标/描述提取明确的
  root_domain/subdomain/ip/cidr 并登记为 task_scope；只登记明确写出的、
  拿不准选更精确的；不处理 company(任务刚建公司通常未入库、名字解析不上，
  留给 plan 阶段)
- MaxTurns 4→6；server createGoals 传入 AssetStore + 数字 taskID

Co-Authored-By: Claude Opus 4.8 <[email protected]>

server/goals.go

@@ -3,6 +3,7 @@ package server
 import (
 	"context"
 	"log"
+	"strconv"
 	"strings"
 
 	"github.com/Autumn-27/artex/agent"
@@ -28,7 +29,12 @@ func (s *Server) createGoals(ctx context.Context, t *Task, emit func(db.Activity
 	// splitter (which shredded URLs / made meaningless 2-way splits).
 	var specs []goalSpec
 	if cfg, ok := s.goalsLLMConfig(t); ok {
-		for _, g := range agent.DecomposeGoals(ctx, cfg, t.Goal, t.Description, emit) {
+		var as *db.AssetStore
+		if s.m != nil {
+			as = s.m.Assets()
+		}
+		taskID, _ := strconv.ParseInt(t.ID, 10, 64)
+		for _, g := range agent.DecomposeGoals(ctx, cfg, t.Goal, t.Description, as, taskID, emit) {
 			if strings.TrimSpace(g.Text) != "" {
 				specs = append(specs, goalSpec{Text: g.Text, VulnClass: g.VulnClass})
 			}