Function normalize_permission_rule 

pub fn normalize_permission_rule(raw: &str) -> String

Normalize a permission rule string to its semantic form.

This transforms raw tool-name rules into semantic rules before compilation. For example:

• "read_file" → "read"
• "read_file(/src/**/*.rs)" → "read(/src/**/*.rs)"
• "mcp__server__tool" → unchanged (MCP rules pass through)
• "read" → unchanged (already semantic)