Keep the agent-intent import inside the intent adapter

Why: the command has to load guard overlays without naming agent-intent types. Only adapters/intent may import that library.
Evidence: GOWORK=off go test -count=1 in adapters/intent and cmd/agent-squad passed.
Impact: CLI calls NewFromOverlay. Guard domains stay guard.
Refs: D1
Co-authored-by: Cursor <cursoragent@cursor.com>

adapters/intent/gate.go

@@ -31,6 +31,19 @@ type Options struct {
 	Roots []string
 }
 
+// NewFromOverlay 从 JSON overlay 构造闸门，并把 guard 域标成受保护域。
+// 命令行用它，这样命令本身不必 import agent-intent。
+func NewFromOverlay(ctx context.Context, fsys fs.FS, roots ...string) (*Gate, error) {
+	return New(ctx, Options{
+		IntentOptions: intent.Options{
+			GuardDomains:     []string{"guard"},
+			ProtectedDomains: []string{"guard"},
+		},
+		FS:    fsys,
+		Roots: roots,
+	})
+}
+
 // New 构造闸门。没有任何意图来源时返回 (nil, nil)——引擎拿到 nil IntentGate，
 // 行为与原实现一致（T0 行为解耦）。
 func New(ctx context.Context, o Options) (*Gate, error) {