feat(v4.0.0): Complete metadata/vector separation architecture with Azure support

This commit completes the core v4.0.0 architecture changes for billion-scale
performance with metadata/vector separation. NO RELEASE YET - remaining optimizations
and testing required before production release.

## Core v4.0.0 Architecture Changes

### Type System Updates
- Fixed all TypeScript compilation errors (zero errors achieved)
- Updated HNSWNoun/HNSWVerb to separate core fields from metadata
- Implemented HNSWNounWithMetadata/HNSWVerbWithMetadata for API boundaries
- Added required 'noun' field to NounMetadata for semantic structure
- Renamed verb.type to verb.verb for consistency

### Storage Adapter Updates
**All adapters updated for v4.0.0 two-file storage pattern:**
- memoryStorage: Proper metadata/vector separation
- fileSystemStorage: Two-file pattern with sharding
- opfsStorage: Browser persistent storage updated
- s3CompatibleStorage: AWS/MinIO/DigitalOcean support
- r2Storage: Cloudflare R2 optimization
- gcsStorage: Google Cloud with ADC support
- **azureBlobStorage: NEW - Full Azure Blob Storage support**

### Storage Features
- BaseStorage: Internal vs public method separation (_getNoun vs getNoun)
- Two-file storage: Vectors in one file, metadata in another
- Change tracking: getChangesSince return type updated
- Pagination: getNounsWithPagination returns WithMetadata types

### Azure Blob Storage Integration (NEW)
- Native @azure/storage-blob SDK integration
- Four authentication methods:
  * DefaultAzureCredential (Managed Identity) - recommended
  * Connection String - simplest setup
  * Account Name + Key - traditional auth
  * SAS Token - delegated access
- High-volume mode with write buffering
- Adaptive backpressure for throttling
- UUID-based sharding for billion-scale
- Full HNSW support with graph persistence

### Utility Updates
- EmbeddingManager: Updated to accept Record<string, unknown>
- LSMTree: Wrapped data in NounMetadata structure with 'noun' field
- EntityIdMapper: Fixed nested metadata.data structure access
- MetadataIndex: Fixed field type inference integration
- PeriodicCleanup: Updated for new metadata structure

### Core API Updates
- Brainy: Updated verb property access from v.type to v.verb
- ConfigAPI: Fixed NounMetadata access patterns
- DataAPI: Updated metadata handling

### Documentation Updates
- CREATING-AUGMENTATIONS.md: v4.0.0 breaking changes guide
- DEVELOPER-GUIDE.md: Migration checklist and examples
- COMPLETE-REFERENCE.md: v4.0.0 architecture improvements
- **finite-type-system.md: NEW - Revolutionary type system benefits**

### Build & Dependencies
- Zero TypeScript compilation errors
- Added @azure/storage-blob and @azure/identity
- 591 tests passing (23 timeout in long-running neural tests)

## What's NOT in This Release
This is a work-in-progress commit. Before v4.0.0 release we need:
- Storage adapter optimizations (batch operations, compression)
- Azure blob tier management (Hot/Cool/Archive)
- Cost optimization implementations
- Additional performance testing at billion-scale
- Migration guides for v3.x users

## Testing
- Clean build: ✅
- Type checking: ✅ (zero errors)
- Test suite: ✅ (591/614 passing, timeouts in neural tests only)

🔐 Generated with Claude Code
https://claude.com/claude-code

Co-Authored-By: Claude <noreply@anthropic.com>

docs/augmentations/DEVELOPER-GUIDE.md

@@ -1,6 +1,49 @@
 # 🛠️ Brainy Augmentation Developer Guide
 
-> **How to create, test, and use augmentations in Brainy 2.0**
+> **How to create, test, and use augmentations in Brainy v4.0.0**
+>
+> **⚠️ v4.0.0 Update**: This guide has been updated with breaking changes for metadata structure and type system improvements.
+
+## v4.0.0 Migration Guide
+
+### What Changed?
+
+1. **Metadata Structure**: All metadata now requires type fields (`noun` or `verb`)
+2. **Property Rename**: `verb.type` → `verb.verb` for relationships
+3. **Two-File Storage**: Vectors and metadata stored separately for performance
+4. **Return Types**: Storage methods distinguish between internal (pure) and public (WithMetadata) returns
+
+### Migration Checklist
+
+- [ ] Update metadata creation to include required `noun` field
+- [ ] Change `verb.type` to `verb.verb` in all relationship code
+- [ ] Update storage adapter methods to follow internal/public pattern
+- [ ] Ensure metadata access uses correct structure
+
+### Quick Migration Example
+
+```typescript
+// ❌ v3.x
+const verb = {
+  type: 'relatedTo',
+  sourceId: 'a',
+  targetId: 'b'
+}
+if (verb.type === 'relatedTo') { ... }
+
+// ✅ v4.0.0
+const verb = {
+  verb: 'relatedTo',
+  sourceId: 'a',
+  targetId: 'b'
+}
+const metadata: VerbMetadata = {
+  verb: 'relatedTo',
+  sourceId: 'a',
+  targetId: 'b'
+}
+if (verb.verb === 'relatedTo') { ... }
+```
 
 ## Quick Start: Your First Augmentation
 
@@ -12,12 +55,12 @@ export class MyFirstAugmentation extends BaseAugmentation {
   readonly timing = 'after' as const       // When to run: before | after | both
   readonly operations = ['add'] as const  // Which operations to hook
   readonly priority = 10                    // Execution order (lower = first)
-  
+
   protected async onInit(): Promise<void> {
     // Initialize your augmentation
     console.log('MyFirstAugmentation initialized!')
   }
-  
+
   async execute<T = any>(
     operation: string,
     params: any,
@@ -26,12 +69,18 @@ export class MyFirstAugmentation extends BaseAugmentation {
     // Your augmentation logic
     if (operation === 'add') {
       console.log('Noun added:', params.noun)
+
+      // v4.0.0: Access metadata correctly
+      if (params.noun?.metadata) {
+        console.log('Noun type:', params.noun.metadata.noun)  // Required field
+      }
+
       // You can access the brain instance
       const stats = await context?.brain.getStats()
       console.log('Total nouns:', stats.totalNouns)
     }
   }
-  
+
   protected async onShutdown(): Promise<void> {
     // Cleanup
     console.log('MyFirstAugmentation shutting down')