Separate prompt field alongside the lyrics box

Description: Add a dedicated field for style instructions and tags, separate from the lyrics box. At the moment Custom Lyrics mode has a single field that holds both the user’s lyrics and any tags or instructions. The two share the same character limit, so users writing longer lyrics have to cut words to make room for the instructions that shape how those words are performed. What users are asking for: A separate input beside the lyrics box for tags and style direction Instructions that don’t consume lyric character space The ability to write full lyrics without stripping them back to fit tags in This affects users writing their own lyrics most, since they’re the ones filling the field with words rather than relying on the AI to generate them.