Sidebar descender test: assert leading-tight per account block, order-independent

Parse each account-block div's class set instead of capturing the token before
the collapsible marker positionally. Every flex-col block hidden on icon collapse
must carry leading-tight and never leading-none, checked per block, so dropping
the class from one block can no longer pass by hiding behind another.

tests/studio/test_studio_text_descender_clipping.py

@@ -34,17 +34,18 @@ def test_model_selector_trigger_label_uses_leading_tight():
 
 def test_sidebar_account_block_uses_leading_tight():
     src = _read(APP_SIDEBAR)
-    # Match the account-block parent div regardless of its gap utility; this
-    # guard is about the leading-* class, not the spacing.
-    pattern = re.compile(
-        r'<div\s+className="flex\s+flex-col\s+gap-\S+\s+(\S+)\s+group-data-\[collapsible=icon\]:hidden">',
-    )
-    matches = pattern.findall(src)
-    assert matches, "could not find sidebar account-block parent div"
-    leading_classes = [m for m in matches if m.startswith("leading-")]
-    assert leading_classes, f"no leading-* class on sidebar account-block parent: {matches}"
-    for cls in leading_classes:
-        assert cls == "leading-tight", f"sidebar account-block must use leading-tight, got: {cls}"
+    # Identify each account-block parent div by its class SET (order-independent),
+    # not a positional regex: a flex-col column hidden when the sidebar collapses
+    # to icons. EVERY such block must carry leading-tight and never leading-none,
+    # checked per block -- a filter-then-"any" check would let one block drop the
+    # class and hide behind another, defeating the per-block descender guard.
+    div_classes = re.findall(r'<div\s+[^>]*className="([^"]*)"', src)
+    markers = {"flex", "flex-col", "group-data-[collapsible=icon]:hidden"}
+    blocks = [c.split() for c in div_classes if markers <= set(c.split())]
+    assert blocks, "could not find sidebar account-block parent div"
+    for classes in blocks:
+        assert "leading-tight" in classes, f"sidebar account-block must use leading-tight, got: {classes}"
+        assert "leading-none" not in classes, f"leading-none must not coexist with truncate here: {classes}"
 
 
 def test_no_truncate_plus_leading_none_in_changed_files():