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/vfs/README.md

@@ -332,7 +332,7 @@ const urgent = await vfs.search('', {
 
 ## Advanced Features
 
-> **Note:** See [VFS ROADMAP](./ROADMAP.md) for planned advanced features like version history, distributed filesystem, and more.
+> **Note:** See [VFS ROADMAP](./ROADMAP.md) for planned advanced features like version history and more.
 
 ## Integration Possibilities
 
@@ -351,7 +351,6 @@ Brainy VFS is designed for speed and scale:
 **PROJECTED at larger scales (not yet tested):**
 - **Vector search** <100ms for millions of files (projected)
 - **Streaming support** for files of any size (architecture supports, see [limitations in ROADMAP](./ROADMAP.md))
-- **Distributed sharding** for billions of files (architecture supports, not tested at scale)
 
 See tests in `tests/vfs/` for actual measured performance.
 
@@ -377,7 +376,7 @@ Brainy VFS fully leverages Brainy's revolutionary Triple Intelligence system:
 | Manual organization | Self-organizing with intelligent fusion |
 | No relationships | Rich knowledge graph with traversal |
 | Static metadata | Dynamic, queryable metadata with field intelligence |
-| Single server | Distributed & federated |
+| Manual scaling | Horizontal read scaling — many readers, one writer |
 
 ## Installation
 
@@ -438,10 +437,10 @@ The VFS is built with production scalability in mind:
  - Parent-child relationship caching
  - Hot path detection and optimization
 
-2. **Distributed Architecture**
- - Sharding by path prefix
- - Read replicas for hot directories
- - CDN integration for static files
+2. **Horizontal Read Scaling**
+ - On-disk store partitioned into 256 hex directory buckets
+ - Many reader processes against one shared store
+ - Single writer keeps the store consistent
 
 3. **Intelligent Indexing**
  - Compound indexes on (parent, name)
@@ -589,49 +588,6 @@ vfs.on('file:added', async (path) => {
 })
 ```
 
-#### **5. Distributed Team Workspace**
-
-Collaborative file management:
-
-```javascript
-// Track file ownership and access
-await vfs.writeFile('/projects/alpha/spec.md', content, {
- metadata: {
- owner: userId,
- team: 'engineering',
- permissions: {
- [userId]: 'rw',
- 'team:engineering': 'r',
- 'others': '-'
- }
- }
-})
-
-// Add collaborative features
-await vfs.addTodo('/projects/alpha/spec.md', {
- task: 'Review security section',
- assignee: 'alice@company.com',
- due: '2024-02-01',
- priority: 'high'
-})
-
-// Track who's working on what
-await vfs.setxattr('/projects/alpha/spec.md', 'locks', {
- section3: {
- user: 'bob@company.com',
- since: Date.now()
- }
-})
-
-// Find all files assigned to a user
-const assigned = await vfs.search('', {
- where: {
- 'todos.assignee': 'alice@company.com',
- 'todos.status': 'pending'
- }
-})
-```
-
 ### Monitoring & Operations (Planned)
 
 > **Note:** Production monitoring features are planned for v1.1. See [ROADMAP](./ROADMAP.md).
@@ -665,27 +621,11 @@ await vfs.init({
 })
 ```
 
-#### **Distributed Cluster**
-```javascript
-const vfs = new VirtualFileSystem()
-await vfs.init({
- distributed: true,
- nodes: [
- 'vfs1.internal:8080',
- 'vfs2.internal:8080',
- 'vfs3.internal:8080'
- ],
- replication: 3,
- consistency: 'eventual'
-})
-```
-
 ## Roadmap & Future Features
 
 See [VFS ROADMAP](./ROADMAP.md) for planned features including:
 - Enhanced streaming support (v1.1)
 - Version history (v1.2)
-- Distributed filesystem (v1.2)
 - AI-powered automation (v2.0)
 - FUSE driver (v2.0 research)
 - And more community-requested features