fix: recipe cover placeholder icons use solid color, not opacity (v0.51.2)

text-foreground/25 alpha compounded wherever an icon's own stroke paths
overlap (chef-hat's brim/band, croissant's curves), reading as a dark
blotch instead of an even tint. Swapped to text-muted-foreground — solid,
themed, no overlap artifacts.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

package.json

@@ -1,6 +1,6 @@
 {
   "name": "epicure",
-  "version": "0.51.1",
+  "version": "0.51.2",
   "private": true,
   "scripts": {
     "dev": "pnpm --filter web dev",