Root cause: when bgp->local_node was reallocated (changed=1), old route
entries remained with stale v_node_info pointing to freed memory. The freed
memory got reused by a BGP peer's NODEINFO_Q, causing route_lookup to return
wrong node_id (b3b2b1b0afaeadac instead of local), which then failed at
etcp_route_send with 'no BGP route' and dropped packets to 10.23.2.1.
Changes:
- route_node.c: route_delete(old) before u_free + route_insert(new) after alloc
- utun_instance.c: remove duplicate route_insert (now atomic inside function)
- route_bgp.c: route_delete before freeing old peer NODEINFO_Q
- route_lib.c: routes_overlap now rejects only exact prefix+network duplicates
- tests/Makefile.am: add route_lib.o to test_route6_lib
Evgeny