Fix path param shadowing by response fields

Path params (owner, repo) now always use the WHERE clause value,
not the response JSON field. Fixes column collision where e.g.
the response's "owner" (a nested user object) would shadow the
path param "owner" (a string), breaking JOINs on those columns.

Author: benaiad

crates/sqlize-core/src/datafusion/arrow_convert.rs

@@ -135,11 +135,23 @@ pub fn json_response_to_batch(
 }
 
 /// Extract a scalar value from a JSON item for a given column.
+///
+/// Path params always use the pushed value (the user's WHERE clause),
+/// not the response field — even if the response has a field with the
+/// same name (e.g., `owner` is both a path param and a nested user object).
 fn extract_value(
     item: &serde_json::Value,
     col: &Column,
     param_values: &HashMap<ColumnName, String>,
 ) -> Scalar {
+    // Path params: always use the pushed value
+    if col.role.is_required() {
+        if let Some(v) = param_values.get(&col.name) {
+            return Scalar::String(v.clone());
+        }
+    }
+
+    // Response fields: check JSON first, fall back to param values
     if let Some(map) = item.as_object() {
         let col_name = col.name.as_str();
         if let Some(v) = find_in_json(map, col_name) {