feat: remove legacy ImportManager, standardize getStats() API

- Removed ImportManager class and exports (use brain.import() instead)
- Fixed all documentation: getStatistics() → getStats()
- Updated 41 files across codebase for consistency
- Removed ImportManager section from API docs
- Added v3.30.0 migration guide to CHANGELOG

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

docs/augmentations/COMPLETE-REFERENCE.md

@@ -141,7 +141,7 @@ brain.find({ where: { category: 'tech' } })
 **Auto-enabled**: Always active  
 **Purpose**: Performance metrics and statistics collection
 ```typescript
-brain.getStatistics()        // Comprehensive metrics
+brain.getStats()        // Comprehensive metrics
 ```
 
 ### MonitoringAugmentation
@@ -403,7 +403,7 @@ brain.disableAugmentation('cache')
 ### Performance issues?
 ```typescript
 // Check augmentation overhead
-const stats = brain.getStatistics()
+const stats = brain.getStats()
 console.log(stats.augmentations)
 
 // Disable non-critical augmentations

docs/augmentations/DEVELOPER-GUIDE.md

@@ -27,7 +27,7 @@ export class MyFirstAugmentation extends BaseAugmentation {
     if (operation === 'add') {
       console.log('Noun added:', params.noun)
       // You can access the brain instance
-      const stats = await context?.brain.getStatistics()
+      const stats = await context?.brain.getStats()
       console.log('Total nouns:', stats.totalNouns)
     }
   }
@@ -187,7 +187,7 @@ class ContextAwareAugmentation extends BaseAugmentation {
     if (!brain) return
     
     // Use any brain method
-    const stats = await brain.getStatistics()
+    const stats = await brain.getStats()
     const size = await brain.size()
     const results = await brain.search('query')