Initial commit: ClawSync v0.1.0

8-crate pure-Rust workspace for revision-aware HDF5 sync.

## Crates
- clawhdf5-onion: ClawOnion VFD — page-level versioned HDF5 storage,
  binary format, writer/reader, branch DAG, GC, snapshots, provenance
- clawsync-core: BLAKE3, xxHash3, FastCDC (+ SIMD NEON), zstd/lz4
- clawsync-onion: IBLT sketch, Merkle tree differ, packet differ/merger,
  ClawSyncManifest, SyncSelector
- clawsync-hdf5: dataset-level manifest, differ, patcher, wire payload
  reconstruction (apply_received_payloads)
- clawsync-transport: TCP, QUIC (quinn 0.11/TLS 1.3), SyncPeer abstraction,
  length-prefixed rkyv wire protocol (21 SyncMessage variants)
- clawsync-agent: OnionMemory, SyncScheduler, TcpSyncBackend,
  PeerCapabilities negotiation
- clawsync-fs: CDC-based delta sync for any file type; FsSyncClient/Server,
  W=16 pipelining, atomic writes
- clawsync-cli: push/pull/serve/hdf5-sync/serve-hdf5/sync/serve-fs +
  all local management commands; --quic on all network commands

## Key features
- IBLT pre-flight: O(revision count) vs rsync's O(file size)
- W=16 sliding-window push: 13–15x speedup over stop-and-wait at WAN RTT
- Dataset-granular HDF5 sync: only modified datasets transferred
- CDC delta for any file type: insertion-stable chunk boundaries
- Full revision DAG: branch, merge, rollback, export, snapshot, GC
- QUIC transport: TLS 1.3, per-message streams via quinn 0.11

## Tests
~573 passing (default features); ~589 with --features simd-cdc

## Performance (Apple Silicon)
- Reconstruct rev=100: 68 µs (target ≤ 1 ms)
- BLAKE3 Rayon 1 MB: 10.3 GiB/s (target ≥ 5 GB/s)
- GC 500 revisions: 20.6 µs (target ≤ 2 s)
- W=16 vs W=1 at 5 ms RTT: 14.8x speedup
- No-op pre-flight at 16 MB: 4 ms vs rsync 35 ms (7.8x)

Co-Authored-By: Claude Sonnet 4.6 <[email protected]>

crates/clawsync-onion/README.md

@@ -0,0 +1,42 @@
+# clawsync-onion
+
+ClawSync onion-aware revision diff, layer packaging, and manifest protocol.
+
+## Overview
+
+`clawsync-onion` sits between the onion storage layer (`clawhdf5-onion`) and the
+transport layer (`clawsync-transport`). It knows how to:
+
+1. Compute which revisions a remote node is missing (`diff_revisions`)
+2. Package those revisions as `OnionLayerPacket` wire messages
+3. Apply incoming packets to a local `OnionFile` (`merge_packets`)
+4. Build and parse `ClawSyncManifest` for pre-flight negotiation
+
+## Key Types
+
+### `diff_revisions(local, remote_head) -> Vec<OnionLayerPacket>`
+
+Given a local `OnionFile` and the remote's HEAD revision number, returns the
+minimal set of packets needed to bring the remote up to date — in ascending
+revision order, ready to send.
+
+### `merge_packets(onion, packets, flush) -> MergeStats`
+
+Applies incoming packets to a local `OnionFile`. Verifies BLAKE3 integrity for
+each packet, skips already-present revisions (idempotent), and optionally flushes.
+
+### `ClawSyncManifest`
+
+Compact summary of an `OnionFile` exchanged during sync negotiation. Contains
+revision count, HEAD revision, per-revision BLAKE3 hashes, and a set for O(1)
+revision lookup.
+
+### `OnionLayerPacket`
+
+Wire representation of a single revision: revision number, branch ID, parent
+revision, BLAKE3 root, and a list of `OnionPage` (h5_offset + page bytes).
+Serialized with rkyv for zero-copy deserialization.
+
+## License
+
+MIT — see repository root.