v3.7.0 — Phase 5 Part 4: CRDT Vector-Clock Blackboard Backend

[Jovancoding]

v3.7.0 — Phase 5 Part 4: CRDT Vector-Clock Blackboard Backend

## What's New

### CRDT-Based Synchronization
A `CrdtBackend` implementation of `BlackboardBackend` that uses vector clocks and conflict-free merge semantics to synchronize state across multiple nodes (processes or machines) — no central coordinator required.

```typescript
import { CrdtBackend } from 'network-ai';

const nodeA = new CrdtBackend('node-a');
const nodeB = new CrdtBackend('node-b');

nodeA.write('status', 'idle', 'agent-1');
nodeB.write('status', 'busy', 'agent-2');

nodeA.sync(nodeB); // bidirectional merge

// Both nodes converge on the same deterministic value
console.log(nodeA.read('status')?.value === nodeB.read('status')?.value); // true

New Exports

Export	Description
CrdtBackend	CRDT-based backend — write(), delete(), merge(), sync()
CrdtEntry	BlackboardEntry + vectorClock, nodeId, deleted fields
VectorClock	Record<string, number> — maps nodeId to logical counter
CrdtBackendOptions	{ nodeId?: string }
tickClock(clock, nodeId)	Increment a node's counter; returns new clock
mergeClock(a, b)	Component-wise max of two clocks; returns new clock
happensBefore(a, b)	true if a causally preceded b
isConcurrent(a, b)	true if neither clock happened-before the other
compareClock(a, b)	Returns -1 | 0 | 1 for causal ordering
mergeEntry(a, b)	Conflict-free merge: causal order → timestamp → nodeId tiebreak

Conflict Resolution

Concurrent writes are resolved deterministically — no randomness, no arrival-order dependency:

1. Causal order — if one write happened-before the other, the later one wins
2. Timestamp tiebreak — for concurrent writes, the later wall-clock timestamp wins
3. NodeId tiebreak — for identical timestamps, the lexicographically larger nodeId wins

Tombstone Deletes

delete() records a deleted: true tombstone so deletions propagate correctly through merge() and sync() to all nodes.

Testing

• 117 new tests (test-phase5d.ts) — vector clock primitives, causal/concurrent merge, 3-node convergence, tombstone propagation, TTL, commutativity, idempotency, export verification
• 742 total passing tests

No Breaking Changes

All existing backends (FileBackend, MemoryBackend, RedisBackend) are unchanged.

Full Changelog

See CHANGELOG.md for details.

<hr /><em>This discussion was created from the release <a href='https://github.com/jovanSAPFIONEER/Network-AI/releases/tag/v3.7.0'>v3.7.0 — Phase 5 Part 4: CRDT Vector-Clock Blackboard Backend</a>.</em>