Cardano Updates

Move Leios dedup, offer tracking, and fetch routing (500 lines, 11 fields)
into a self-contained leios_tracker module. Coordinator delegates via a
narrow interface, dropping from 2288 to 1788 lines. Tracker has its own
synchronous unit tests; 293 total tests pass.

Co-Authored-By: Claude Opus 4.6 (1M context) <[email protected]>

Comparison to Praos spec, noting work still to do.  Major items:

- Peer management (promote/demote/churn)
- Pipelining

Both are known and will be next up following a coordinator
refactor

Co-Authored-By: Claude Opus 4.6 (1M context) <[email protected]>

Decouple TCP accept from handshake so one slow peer no longer blocks
all inbound connections.  Each handshake now runs as an independent
tokio task, gated by a semaphore (--max-handshaking, default 64) and
a per-IP connection cap (--max-connections-per-ip, default 3).

Co-Authored-By: Claude Opus 4.6 (1M context) <[email protected]>

Switch mux from RoundRobin to StrictPriority scheduler so Praos
protocols always outprioritize Leios, preventing head-of-line blocking.
Add named priority constants, fix KeepAlive/PeerSharing/Leios priority
assignments, consolidate deferred items into Future Work section.

Co-Authored-By: Claude Opus 4.6 (1M context) <[email protected]>

codec.rs wraps mux channels with CBOR framing — belongs in mux/.
protocol.rs defines the protocol state machine framework — belongs
in protocols/. Re-export from parent modules so imports become
crate::mux::{CodecSend,CodecRecv} and crate::protocols::{Protocol,
Runner,Agency,Role,ProtocolError}. Update all ~40 import sites.
238 tests pass.

Co-Authored-By: Claude Opus 4.6 (1M context) <[email protected]>

Wire LeiosNotify (ID 18) and LeiosFetch (ID 19) into the per-peer task
architecture behind a `leios_enabled` config flag (default false).

- LeiosStore: content-addressed blob store for EBs/votes (separate from
  ChainStore since Leios data is keyed by (slot, hash), not a linear chain)
- Client tasks: spawn_leios_notify (continuous request_next loop),
  spawn_leios_fetch (command-driven, like BlockFetch)
- Server handlers: serve_leios_notify (from LeiosStore + subscribe),
  serve_leios_fetch (block/txs/vote lookups)
- Types: 6 PeerEvent, 2 PeerCommand, 5 NetworkEvent, 3 NetworkCommand variants
- Coordinator: stub-forwards Leios events, populates LeiosStore on fetch
- Wiring: peer_task, responder_task, duplex_task all conditionally register
  and spawn Leios protocol sub-tasks
- CLI: --leios flag on serve (synthetic EB/vote generation) and multi-follow
  (logs Leios notifications) for local end-to-end testing

247 total tests (9 new). Locally tested: serve --leios -> multi-follow --leios.

Co-Authored-By: Claude Opus 4.6 (1M context) <[email protected]>

All 6 N2N mini-protocols now implemented (147 tests). Multi-peer
coordination layer remains TBD for Phase 3.

Co-Authored-By: Claude Opus 4.6 (1M context) <[email protected]>

Update workspace structure (types/ module, mux/codec.rs, protocols/
protocol.rs, leios_notify/, leios_fetch/). Update header/block design
decision from opaque to parsed. Mark Phase 4a-4c as complete. Fix
file paths and test counts in implementation plan.

Co-Authored-By: Claude Opus 4.6 (1M context) <[email protected]>

Implement the TxSubmission mini-protocol (protocol ID 4, version 2) —
pull-based transaction dissemination with blocking/non-blocking modes,
flow control, and full CBOR codec with indefinite-length inner lists.

Includes client-side run_client helper, server handler in fake server,
and CLI 'submit' command with single-tx and Poisson stream modes.
20 new tests (129 total), live-tested against fake server.

Co-Authored-By: Claude Opus 4.6 (1M context) <[email protected]>

Choose thread-per-peer with shared coordinator over Pallas v2
event-driven (single-threaded bottleneck) and Haskell actor model
(over-engineered for ~20 peers). Document PeerHandle sketch,
peer-agnostic consensus interface, and ordering rationale
(multi-peer before Leios protocols).

Co-Authored-By: Claude Opus 4.6 (1M context) <[email protected]>

Sub-phases 4a-4f: LeiosNotify/LeiosFetch protocols, Praos header/body
extensions, per-peer task integration, coordinator/ChainStore extensions,
and priority scheduling. Working assumptions: protocol IDs 18/19, opaque
types, two protocols initially, freshest-first deferred.

Co-Authored-By: Claude Opus 4.6 (1M context) <[email protected]>

Add detailed plan for peer temperature lifecycle (Cold/Warm/Hot),
dynamic sub-task management, and churn policy. Moderate scope,
no consensus dependency, can be done before or after Phase 4.

Co-Authored-By: Claude Opus 4.6 (1M context) <[email protected]>

Security fixes:
- read_segment now validates payload_len against max_payload before
  allocating, preventing OOM from malicious segment headers
- CodecRecv enforces max_buffer (default 2.5MB) to prevent unbounded
  buffer growth from crafted CBOR that never completes decoding
- Demuxer passes configured sdu_size as the segment payload limit

Test vectors captured from backbone.cardano.iog.io:3001:
- ProposeVersions and AcceptVersion raw bytes validated against our
  encoder output (byte-for-byte match ensures wire compatibility)

New tests (19 added, 50 total):
- Wire: oversized payload rejection, live segment headers, timestamp wrap
- Codec: buffer overflow rejection, large cross-segment messages, channel close
- Handshake codec: unknown tag, truncated payload, live vector decode
- N2N: v7-v10 2-field format, live bytes decode, invalid CBOR, key order

Also: net-cli capture command, CLAUDE.md test vector workflow, .gitignore

Co-Authored-By: Claude Opus 4.6 (1M context) <[email protected]>

- Cap version table entries at 256 and version mismatch list at 256
  in handshake codec, preventing unbounded allocation from crafted
  CBOR map/array lengths
- Switch demuxer from blocking send to try_send -- if a protocol's
  channel is full, the connection is torn down instead of blocking
  the demuxer (which would stall all protocols on the connection)
- Add test for oversized version table rejection

Co-Authored-By: Claude Opus 4.6 (1M context) <[email protected]>

New `follow` CLI command that jumps to the current chain tip and prints
each new block as it arrives. Reconnects with exponential backoff on
failure, using a rolling window of known points for efficient
re-intersection. Shared connection helper extracted to reduce duplication
across CLI commands. Live-tested against Cardano mainnet.

Co-Authored-By: Claude Opus 4.6 (1M context) <[email protected]>

Phase 1 steps 1-6: the core transport and multiplexing layers.

- Workspace setup: net-core (library) + net-cli (binary) crates
- bearer/: trait-based transport abstraction with TcpBearer and MemBearer
- mux/wire: 8-byte segment header encode/decode, segment read/write,
  payload fragmentation into SDUs
- mux/channel: split ChannelSend/ChannelRecv halves (pipelining-ready)
- mux/scheduler: Scheduler trait with RoundRobin and StrictPriority
- mux/egress: muxer task with per-protocol staging buffers and
  scheduler-driven segment writing
- mux/ingress: demuxer task with per-protocol dispatch and configurable
  ingress buffer limits (overflow = connection teardown per spec)
- mux/mod: Mux assembly tying it all together with register() and run()

16 tests covering wire format round-trips, scheduler behavior, bearer
data exchange, and full mux integration (single-protocol, bidirectional,
multi-protocol) over MemBearer.

Co-Authored-By: Claude Opus 4.6 (1M context) <[email protected]>