Function resolve_callee 

pub fn resolve_callee(
    graph: &CodeGraph,
    callee_name: &str,
    caller_file: &Path,
    imported_names: &[String],
) -> Option<SymbolId>

Resolve a callee name to the best-matching SymbolId. Priority:

1. Same file (private helper in same file) — score 4
2. Imported name (appears in caller’s import list) — score 3
3. Same directory — score 2
4. Same top-level crate/package — score 1
5. Any match — score 0