fix: hover card, preferences modal, timeline scroll, multi-drag

- ResourceHoverCard: add isInitialLoading to useEffect deps so
  mouseover/mouseout listeners attach after canvas mounts
- PreferencesModal: lift prefsOpen state to AppShell, render modal
  outside sidebar's backdrop-blur stacking context
- Timeline page: constrain to max-h-[100dvh] overflow-hidden so
  horizontal scrollbar is accessible without scrolling to bottom
- Multi-drag: pass selectedAllocationIds from ref at drag completion
  to prevent stale closure in onMultiDragComplete callback

Co-Authored-By: claude-flow <ruv@ruv.net>

apps/web/src/app/(app)/timeline/page.tsx

@@ -15,7 +15,7 @@ const TimelineView = dynamic(
 
 export default function TimelinePage() {
   return (
-    <div className="app-page flex h-full flex-col gap-5 pb-6">
+    <div className="app-page flex max-h-[100dvh] flex-col gap-5 overflow-hidden pb-6">
       <div className="app-page-header">
         <div>
           <h1 className="app-page-title">Timeline</h1>