fix: correct YAML frontmatter, convert images to proper WebP format

- Moved image: field from outside to inside YAML frontmatter (50 files)
- Converted all 56 non-WebP images to proper WebP format via ImageMagick
- Fixed Python shebangs for portability
- Updated source fields in 2 Task 3 recipes

Gochugaru Honey Salmon.cook

@@ -1,4 +1,3 @@
-image: https://roux.roo.lol/recipe-images/gochugaru-honey-salmon.webp
 ---
 title: Gochugaru Honey Salmon
 servings: 2
@@ -8,6 +7,7 @@ tags: crispy rice,garnish-and-gather,gochugaru,korean,salmon
 source: Unknown
 description: Salmon with spicy honey sauce served with crispy rice, broccoli, and carrots
 prep_time: 25 minutes
+image: https://roux.roo.lol/recipe-images/gochugaru-honey-salmon.webp
 ---
 
 In a #pot{}, bring 1 1/2 cups @water{} to a boil for @rice{3/4 cup, long grain}.