fix: Fix Svelte 5 reactivity issues in matches page and update API handling

- Fix toast notification imports: change from showToast to toast.success/error
- Remove hover preloading from app.html and Tabs component
- Fix match rounds API handling with safe parsing for incomplete data
- Fix pagination timestamp calculation (API returns Unix timestamp, not ISO string)
- Refactor matches page state management to fix reactivity issues:
  - Replace separate state variables with single matchesState object
  - Completely replace state object on updates to trigger reactivity
  - Fix infinite loop in intersection observer effect
  - Add keyed each blocks for proper list rendering
- Remove client-side filtering (temporarily) to isolate reactivity issues
- Add error state handling with nextPageTime in matches loader

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

src/lib/components/ui/Tabs.svelte

@@ -59,7 +59,6 @@
 				class:tab-active={isActive(tab)}
 				class:tab-disabled={tab.disabled}
 				aria-disabled={tab.disabled}
-				data-sveltekit-preload-data="hover"
 			>
 				{tab.label}
 			</a>