refactor(8.0)!: remove distributed clustering subsystem — inert/orphaned, scale is single-process + native provider

The distributed-clustering subsystem never ran in production: it was inert,
orphaned dead code (faked consensus, stub replication, no live wiring, and it
did not interoperate with the 8.0 Db API). Brainy 8.0 is a single-process
library. Scale is single-process + the optional native provider
(@soulcraft/cortex, on-disk DiskANN to 10B+ vectors) + per-tenant pools +
horizontal read scaling (many reader processes, one writer).

Removed:
- src/distributed/ entirely (coordinator, shardManager, cacheSync,
  readWriteSeparation, queryPlanner, healthMonitor, configManager,
  hashPartitioner, shardMigration, domainDetector, storageDiscovery, http/network
  transports). ReaderMode/HybridMode relocated to src/storage/operationalModes.ts
  (slimmed to the live surface).
- src/types/distributedTypes.ts; config.distributed field + JSDoc;
  coreTypes distributedConfig; memoryStorage distributedConfig persistence.
- DistributedRole enum + src/config/distributedPresets.ts and the orphaned
  src/config/extensibleConfig.ts (config/augmentation registry built on removed
  cloud adapters + distributed presets), plus their src/index.ts re-exports.
- 13 BRAINY_* cluster env vars; the storage setDistributedComponents hook;
  enableDistributedSearch (dead config flag); the metadata partition field;
  the distributed_ reserved key prefix.
- Orphaned src/storage/readOnlyOptimizations.ts (zero importers).
- Tests targeting the subsystem: distributed-demo, distributed-cluster helper,
  distributed-transactions, sharding-transactions.
- Docs: EXTENDING_STORAGE.md (deleted); scrubbed distributed/cluster/Raft/
  shard-manager/multi-node prose from v3-features, enterprise-for-everyone,
  augmentations-actual, complete-feature-list, vfs/README, vfs/ROADMAP,
  vfs/VFS_CORE, capacity-planning, transactions, MIGRATION-V3-TO-V4,
  storage-architecture; reframed scale prose to the 8.0 model.

Kept: src/storage/sharding.ts (local-disk 256-bucket directory sharding via
getShardIdFromUuid — used live by baseStorage, unrelated to clustering);
the multi-process mode: 'reader' | 'writer' roles; semantic/HNSW clustering.

RELEASES.md: added a removed-surfaces row documenting the cut and the 8.0
scale model.

docs/features/complete-feature-list.md

@@ -66,7 +66,7 @@ import { BatchProcessingAugmentation } from 'brainy'
 ```typescript
 import { ConnectionPoolAugmentation } from 'brainy'
 // Auto-scaling connection management
-// Optimized for distributed operations
+// Optimized for high-concurrency workloads
 ```
 
 ### 7. Request Deduplicator ✅
@@ -100,8 +100,7 @@ import { MemoryStorageAugmentation } from 'brainy'
 ### 11. Server Search Conduit ✅
 ```typescript
 import { ServerSearchConduitAugmentation } from 'brainy'
-// Distributed query execution
-// Load balancing across nodes
+// Forwards queries to a remote Brainy server
 ```
 
 ### 12. Neural Import ✅
@@ -155,7 +154,9 @@ await brain.init()
 - **No environment variables needed**
 - **Works in all environments** (Node, Browser, Workers)
 
-## 🏢 Distributed Operation Modes
+## 🏢 Operation Modes
+
+Run many reader processes against one shared on-disk store with a single writer.
 
 ### Reader Mode ✅
 ```typescript
@@ -374,7 +375,7 @@ await brain.init()
 - ✅ All engines (vector, graph, field, neural)
 - ✅ All augmentations (12+)
 - ✅ All storage adapters
-- ✅ All distributed modes
+- ✅ Reader / writer / hybrid operation modes
 - ✅ Complete statistics
 - ✅ GPU support
 - ✅ No feature limitations

docs/features/v3-features.md

@@ -34,58 +34,6 @@ brain.add({ name: "John", email: "john@example.com" }, 'entity')
 - Automatic query optimization
 - Pattern-based query rewriting
 
-## 🏢 Enterprise Features
-
-### Distributed Coordination ✅
-Raft consensus for multi-node deployments:
-```typescript
-import { DistributedCoordinator } from '@soulcraft/brainy'
-
-const coordinator = createCoordinator({
-  nodeId: 'node-1',
-  peers: ['node-2', 'node-3'],
-  electionTimeout: 500
-})
-// Automatic leader election and failover
-```
-
-### Horizontal Sharding ✅
-Consistent hashing for data distribution:
-```typescript
-import { ShardManager } from '@soulcraft/brainy'
-
-const shards = createShardManager({
-  nodes: ['node-1', 'node-2', 'node-3'],
-  replicationFactor: 2,
-  virtualNodes: 150
-})
-// Automatic shard rebalancing on node changes
-```
-
-### Read/Write Separation ✅
-Primary-replica architecture for scale:
-```typescript
-import { ReadWriteSeparation } from '@soulcraft/brainy'
-
-const replication = createReadWriteSeparation({
-  role: 'auto',  // Automatic primary/replica detection
-  consistencyLevel: 'strong',  // or 'eventual'
-  readPreference: 'nearest'
-})
-```
-
-### Cross-Instance Cache Sync ✅
-Version vector-based cache synchronization:
-```typescript
-import { CacheSync } from '@soulcraft/brainy'
-
-const cache = createCacheSync({
-  nodeId: 'node-1',
-  syncInterval: 100,
-  conflictResolution: 'version-vector'
-})
-```
-
 ## 🔐 Security & Compliance
 
 ### Rate Limiting ✅
@@ -281,14 +229,12 @@ await brain.restore('backup.bin')
 - **10,000+ items**: Sub-10ms search
 - **1M+ operations**: Stable memory usage
 - **100+ concurrent users**: No performance degradation
-- **Multi-node clusters**: Automatic failover
 
 ## 🚫 NOT Implemented (Planned)
 
 These features are documented but NOT yet implemented:
 - GraphQL API (use REST API instead)
 - Kubernetes operators (use Docker)
-- Some distributed features require manual configuration
 
 ---