feat: weighted grid layout, pane list bar, sorted tabs, and idle sound delay

- Replace 70/30 rearranging split with weighted grid: focused pane's
  column/row get 70%, others shrink in place (no spatial reordering)
- Add clickable pane list row below tab bar in both grid and picker modes
- Sort grid tabs numerically by tab number
- Click on focused pane no longer unfocuses it
- Delay idle notification sound by 10s to filter false intermediate alerts
- Bump chrome top from 3 to 4 rows (tab bar, pane list, header, content)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/actions/launch.ts

@@ -65,7 +65,14 @@ export async function doLaunch() {
       targetTabId = createNewGridTab()
       // Rename to match the picker tab number
       const tab = app.gridTabs.find(t => t.id === targetTabId)
-      if (tab) tab.name = `Tab ${tabNum}`
+      if (tab) {
+        tab.name = `Tab ${tabNum}`
+        app.gridTabs.sort((a, b) => {
+          const na = parseInt(a.name.replace(/\D/g, "")) || 0
+          const nb = parseInt(b.name.replace(/\D/g, "")) || 0
+          return na - nb
+        })
+      }
     }
 
     const termW = process.stdout.columns || 120