Function score_file 

pub fn score_file(path: &Path, base_path: &Path) -> u32

Score a file for priority ordering in token budget allocation.

Higher scores = higher priority (included first in budget). Per PDR spec:

• READMEs: 100
• Entry points (main., index., app.*): 90
• Config files: 80
• Source code: 70 - (depth * 10), min 10
• Tests: 30
• Fixtures/generated: 5