Add favorite indicators to recipe cards and improve favorites UI

- Add heart emoji indicators to recipe cards (top-left positioning)
- Show favorites across all recipe list pages (season, category, icon, tag)
- Create favorites utility functions for server-side data merging
- Convert client-side load files to server-side for session access
- Redesign favorite button with emoji hearts (🖤/❤️) and bottom-right positioning
- Fix randomizer array mutation issue causing card display glitches
- Implement consistent favorite indicators with drop shadows for visibility

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

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

src/lib/js/randomize.js

@@ -12,6 +12,6 @@ export function rand_array(array){
 	let time = new Date()
 	const seed = Math.floor(time.getTime()/MS_PER_DAY)
 	let rand = mulberry32(seed)
-	array.sort((a,b) => 0.5 - rand())
-	return array
+	// Create a copy to avoid mutating the original array
+	return [...array].sort((a,b) => 0.5 - rand())
 }