fix: metadata explosion bug - 69K files reduced to ~1K

Critical fix for metadata indexing that was creating 60+ chunk files per entity.

Root cause: Vector embeddings (384-dimensional arrays) were being indexed in
metadata, causing each dimension to create a separate chunk file with numeric
field names ("0", "1", "2", etc.).

Changes:
- Modified extractIndexableFields() to exclude vector/embedding fields
- Added NEVER_INDEX set: ['vector', 'embedding', 'embeddings', 'connections']
- Added safety check to skip arrays > 10 elements
- Preserves small array indexing (tags, categories, roles)

Impact:
- Reduces metadata files from 69,429 → ~1,200 (58x reduction)
- Fixes server initialization hangs
- Fixes metadata batch loading stalling at batch 23
- Fixes VFS getDescendants() hanging with large datasets
- Fixes Graph View UI not loading

Test Results:
- 7/7 integration tests passing
- Verified: 6 chunk files for 10 entities (was 7,210 before fix)
- 611/622 unit tests passing

Files Modified:
- src/utils/metadataIndex.ts - Core fix
- src/coreTypes.ts - HNSWVerb type enforcement with VerbType enum
- src/storage/adapters/* - Include core relational fields in HNSWVerb
- src/storage/adapters/baseStorageAdapter.ts - Type enforcement (HNSWNoun, GraphVerb)
- tests/integration/metadata-vector-exclusion.test.ts - Comprehensive test coverage

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

src/storage/adapters/r2Storage.ts

@@ -728,6 +728,8 @@ export class R2Storage extends BaseStorage {
     const requestId = await this.applyBackpressure()
 
     try {
+      // ARCHITECTURAL FIX (v3.50.1): Include core relational fields in verb vector file
+      // These fields are essential for 90% of operations - no metadata lookup needed
       const serializableEdge = {
         id: edge.id,
         vector: edge.vector,
@@ -736,7 +738,15 @@ export class R2Storage extends BaseStorage {
             level,
             Array.from(verbIds)
           ])
-        )
+        ),
+
+        // CORE RELATIONAL DATA (v3.50.1+)
+        verb: edge.verb,
+        sourceId: edge.sourceId,
+        targetId: edge.targetId,
+
+        // User metadata (if any) - saved separately for scalability
+        // metadata field is saved separately via saveVerbMetadata()
       }
 
       const key = this.getVerbKey(edge.id)
@@ -814,10 +824,19 @@ export class R2Storage extends BaseStorage {
         connections.set(Number(level), new Set(verbIds as string[]))
       }
 
+      // ARCHITECTURAL FIX (v3.50.1): Return HNSWVerb with core relational fields
       const edge: Edge = {
         id: data.id,
         vector: data.vector,
-        connections
+        connections,
+
+        // CORE RELATIONAL DATA (read from vector file)
+        verb: data.verb,
+        sourceId: data.sourceId,
+        targetId: data.targetId,
+
+        // User metadata (retrieved separately via getVerbMetadata())
+        metadata: data.metadata
       }
 
       this.verbCacheManager.set(id, edge)