node_conn_direct:
- ncd_init_cb: skip UP when links_up==0, ncd_up_cb delivers when link comes up
- close/force_close: handle_count safety checks, callback clearing
- open/open_node case 2: create links on reused dead conn
- ncd_create_links: skip duplicate link on same conn (stale->etcp==conn)
- set_callback: optional callback change on live handle
conn_mgr:
- cm_ncd_callback: DOWN only delivers event (handle stays alive)
- cm_ncd_callback: TIMEOUT force_close BEFORE cm_deliver_event
- cm_deliver_event: read handle fields to locals before callback (reentrany-safe)
- INVITE_INFO_REQ/RESP: add duplicate cmd byte for direct-send protocol
- cm_handle_invite_info_resp: search invite by group_id in channel conn_mgr
Android:
- node_id computed by sc_derive_node_id_from_pubkey in C, not Kotlin
- utun_bridge_join_channel: recompute node_id, log mismatch
- invite_link_c: compute nodeId from pubkey via sc_derive_node_id_from_pubkey
- NativeLib.deriveNodeId, InviteLink.kt uses C function