fix(skills): collapse bento spans at 2-col breakpoint, not 720px

Landscape phone (720-1000px band) put the parent grid at 2 columns while the
tile spans (hero span-2, full span-3) only reset at 720px. A span-3 tile in a
2-col grid forced a phantom 3rd column and collapsed the 1fr tracks to
58px 58px 760px, squishing the flagship card to ~132px off the visible area.
Move the span reset to the same 1000px breakpoint the grid drops to 2 columns:
now 446px 446px, hero full-width. Desktop 4-col + portrait 1-col unchanged.

src/components/SkillGroup.astro

@@ -141,9 +141,11 @@ const spanClass =
     padding: 5px 10px;
   }
 
-  /* bento collapses gracefully on narrow screens (grid goes 2-col then 1-col
-     in the parent; spans clamp automatically via grid auto-placement) */
-  @media (max-width: 720px) {
+  /* Below 1000px the parent grid is only 2 columns — so the multi-column spans
+     must collapse to full-width HERE, not at 720px. A `span 3` tile left active
+     in a 2-col grid forces a phantom 3rd column and collapses the 1fr tracks
+     (58px 58px 760px), squishing the first tile to ~130px in landscape phone. */
+  @media (max-width: 1000px) {
     .tile--hero,
     .tile--wide,
     .tile--full {