fix: export ImportManager and add getStats() convenience method

Resolves API accessibility issues reported by Brain Cloud Studio team:

1. Export ImportManager and createImportManager
   - ImportManager class was fully implemented but not exported
   - Consumers can now access AI-powered import features
   - Includes ImportOptions and ImportResult types

2. Add brain.getStats() convenience method
   - Documentation showed getStats() as top-level method
   - Implementation had it nested under brain.counts.getStats()
   - Added convenience method that delegates to counts API
   - Maintains backward compatibility

3. Update API documentation
   - Corrected getStats() signature and return type
   - Added comprehensive ImportManager documentation
   - Included examples for all import patterns

These changes expose existing, tested functionality without
modifying core behavior. All tests pass.

docs/API_REFERENCE.md

@@ -775,14 +775,120 @@ const exported = await data.export({
 
 ---
 
-### `async getStats(): Promise<StorageStats>`
-Gets storage statistics.
+### `getStats(): StatsResult`
+Gets complete statistics about entities and relationships.
 
 **Returns:**
-- `entities` - Entity count
-- `relations` - Relationship count
-- `storageSize` - Storage size in bytes
-- `vectorDimensions` - Embedding dimensions
+```typescript
+{
+  entities: {
+    total: number
+    byType: Record<string, number>
+  }
+  relationships: {
+    totalRelationships: number
+    byType: Record<string, number>
+  }
+  density: number  // relationships per entity
+}
+```
+
+**Example:**
+```typescript
+const stats = brain.getStats()
+console.log(`Total entities: ${stats.entities.total}`)
+console.log(`Total relationships: ${stats.relationships.totalRelationships}`)
+console.log(`Graph density: ${stats.density.toFixed(2)}`)
+```
+
+**Note:** For more granular counting operations, see the `brain.counts` API below.
+
+---
+
+## Import API
+
+### `createImportManager(brain: Brainy): ImportManager`
+Creates an import manager for intelligent data import.
+
+**Example:**
+```typescript
+import { Brainy, createImportManager } from '@soulcraft/brainy'
+
+const brain = new Brainy({ preset: 'memory' })
+await brain.init()
+
+const importer = createImportManager(brain)
+await importer.init()
+```
+
+---
+
+### `async ImportManager.import(source, options?): Promise<ImportResult>`
+Import data from various sources with AI-powered entity detection.
+
+**Parameters:**
+- `source` - String, Buffer, array, or object to import
+- `options.source` - 'data' | 'file' | 'url' | 'auto' (default: 'auto')
+- `options.format` - 'json' | 'csv' | 'text' | 'yaml' | 'auto' (default: 'auto')
+- `options.batchSize` - Batch size for processing (default: 50)
+- `options.autoDetect` - Auto-detect entity types (default: true)
+- `options.typeHint` - Suggested entity type
+- `options.extractRelationships` - Extract relationships (default: true)
+- `options.csvDelimiter` - CSV delimiter character
+- `options.csvHeaders` - CSV has headers (default: true)
+- `options.parallel` - Process in parallel (default: true)
+- `options.maxConcurrency` - Max concurrent operations
+
+**Returns:**
+```typescript
+{
+  success: boolean
+  nouns: string[]        // IDs of imported entities
+  verbs: string[]        // IDs of created relationships
+  errors: string[]
+  stats: {
+    total: number
+    imported: number
+    failed: number
+    relationships: number
+  }
+}
+```
+
+**Examples:**
+
+```typescript
+// Import from CSV file
+const result = await importer.importFile('./data.csv', {
+  format: 'csv',
+  extractRelationships: true
+})
+
+// Import from URL
+const result = await importer.importUrl('https://api.example.com/data.json')
+
+// Import array of objects
+const data = [
+  { name: 'Alice', role: 'Developer' },
+  { name: 'Bob', role: 'Designer' }
+]
+const result = await importer.import(data, {
+  typeHint: NounType.Person,
+  extractRelationships: true
+})
+
+console.log(`Imported ${result.stats.imported}/${result.stats.total} items`)
+console.log(`Created ${result.stats.relationships} relationships`)
+```
+
+**Features:**
+- 🧠 **AI Entity Detection** - Auto-detect entity types from data
+- 🔗 **Relationship Extraction** - Discover connections automatically
+- 📊 **Multi-Format Support** - CSV, JSON, YAML, text files
+- 🚀 **Batch Processing** - Efficient handling of large datasets
+- 💡 **Neural Analysis** - Confidence scoring and insights
+- 🎯 **Smart CSV Parsing** - Auto-delimiter detection
+- 🌐 **URL Imports** - Direct import from web sources
 
 ---