Add strict=True to zip in sync find_paths for consistency

Matches the async find_paths which already uses strict=True, so both
versions raise immediately on a nodes/edges length mismatch.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: gkorland

api/graph.py

@@ -581,7 +581,7 @@ def find_paths(self, src: int, dest: int) -> list[Path]:
             nodes = p.nodes()
             edges = p.edges()
 
-            for n, e in zip(nodes, edges):
+            for n, e in zip(nodes, edges, strict=True):
                 path.append(encode_node(n))
                 path.append(encode_edge(e))