feat(ui): streamline workspace settings and remove sharing

Unify compact workspace controls and panel transitions, move directory actions into the context menu, and remove backlink UI.

Reorganize settings with searchable sections, per-setting resets, shortcut search, and accurate save feedback.

Remove sharing UI, APIs, authentication helpers, and storage code; provide a transactional cleanup script with retirement tests. Reject directories during orphan image cleanup and cover mixed-batch preservation.

internal/auth/auth_test.go

@@ -25,34 +25,20 @@ func newManager(t *testing.T) (*Manager, *time.Time) {
 	return m, &clock
 }
 
-// 登录与分享密码合计 30 次失败后封禁 15 分钟，期间正确密码也被拒绝
+// 登录密码累计 30 次失败后封禁 15 分钟，期间正确密码也被拒绝
 func TestRateLimit(t *testing.T) {
 	m, clock := newManager(t)
-	share := HashSharePassword("share-pass")
 	for i := 0; i < maxFailures-1; i++ {
-		var err error
-		if i%2 == 0 {
-			_, err = m.Login("1.1.1.1", "wrong")
-		} else {
-			err = m.CheckSharePassword("1.1.1.1", share, "wrong")
-		}
-		if !errors.Is(err, ErrBadCredentials) {
+		if _, err := m.Login("1.1.1.1", "wrong"); !errors.Is(err, ErrBadCredentials) {
 			t.Fatalf("第 %d 次失败: %v", i+1, err)
 		}
 	}
-	// 分享密码正确不清零计数
-	if err := m.CheckSharePassword("1.1.1.1", share, "share-pass"); err != nil {
-		t.Fatal(err)
-	}
 	if _, err := m.Login("1.1.1.1", "wrong"); !errors.Is(err, ErrBadCredentials) {
 		t.Fatalf("第 30 次失败: %v", err)
 	}
 	if _, err := m.Login("1.1.1.1", "password123"); !errors.Is(err, ErrRateLimited) {
 		t.Fatalf("封禁期间正确密码也应被拒绝: %v", err)
 	}
-	if err := m.CheckSharePassword("1.1.1.1", share, "share-pass"); !errors.Is(err, ErrRateLimited) {
-		t.Fatalf("封禁同样作用于分享密码: %v", err)
-	}
 	if _, err := m.Login("2.2.2.2", "password123"); err != nil {
 		t.Fatalf("其他来源不受影响: %v", err)
 	}