chore: update project references and add Citron copyright

- Replaced all references to the old project name with Citron.
- Added Citron copyright information alongside existing notices in all files.

rename.sh

@@ -1,7 +1,7 @@
 #!/bin/bash
 
 # Define old and new strings
-old="yuzu"
+old="citron"
 new="citron"
 
 # Find and rename directories first