- Fix NULL block_data deref in stream_send_chunk_cb
- Test B1: create file in <db_dir>/media/, commit to media_files
- Store media_base in ui_state for streaming handler path resolution
- 8/9 tests pass (streaming works but timing issue with SUPER_REPL flood)
- md_handle_block_req: real chunk streaming via etcp_router_on_send_ready
- stream_ctx state machine: backpressure waiter → send chunk → repeat
- content_hash + block_sig on stream completion
- Fallback to author when supernode has no block info
- media_download: author_node_id for peer fallback
- test_media_delivery_full: 8/9 pass (SUPER_HELLO, HAVE_BLOCK, replication, admission, file create)
- Known issue: streaming test hung (BGP route for n1→n2 not established in time)
evgeny