fix(native): remove spurious else-if in Rust findCaller that misattributed 68 call edges (#637)

The Rust `build_call_edges` had an `else if` branch that assigned calls to
the nearest preceding definition even when the call was outside that
definition's span. This caused ~68 call edges to be silently dropped
(caller == target → self-call filter) instead of correctly falling back to
the file node as caller. The JS `findCaller` never had this branch.

Closes #613

Author: carlos-alm

crates/codegraph-core/src/edge_builder.rs

@@ -182,10 +182,6 @@ pub fn build_call_edges(
                             caller_span = span;
                         }
                     }
-                } else if def.line <= call.line && caller_id == file_node_id {
-                    if let Some(id) = def.node_id {
-                        caller_id = id;
-                    }
                 }
             }