fix(combobox): inline chips + input flow as siblings via display:contents

`<Combobox.SelectedTags>` was a nested flex container so the input
always wrapped to its own row below the entire chip block — wasting
the empty space on the last chip row.

Use `display: contents` so each chip becomes a direct flex child of
`<Combobox.Control>`. Chips + input now share the same wrap context:
the input flows on the same row as the last chip when there's room.

`[data-empty]` still toggles to `display: none` so empty-state still
collapses correctly (and the `:has(...:not([data-empty]))` selector
that pins clear/trigger absolutely keeps working).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/uix/eidos/components/combobox/combobox.css

@@ -493,16 +493,18 @@
 	}
 }
 
-/* SelectedTags — inline chip strip inside the Control for multi mode.
- * Hidden when empty so the control collapses back to plain input chrome. */
+/* SelectedTags — logical group for the chip strip. Uses
+ * `display: contents` so each chip becomes a direct flex child of
+ * `<Combobox.Control>` instead of being nested in its own row. This
+ * lets the input flow on the same wrapped row as the last chip
+ * (Material UI Autocomplete behaviour) rather than always dropping
+ * to a fresh row below the whole tag block. */
 [data-combobox-selected-tags] {
-	display: inline-flex;
-	align-items: center;
-	flex-wrap: wrap;
-	gap: var(--space-1-5);
-	min-inline-size: 0;
+	display: contents;
 }
 
+/* Empty state — element stays in DOM (so `:has(...:not([data-empty]))`
+ * still works for layout siblings) but no children render. */
 [data-combobox-selected-tags][data-empty] {
 	display: none;
 }