feat: comprehensive metadata namespace architecture and cleanup system

BREAKING CHANGE: Remove hard delete option from deleteVerb() for consistent API

- Add complete metadata namespace architecture with O(1) soft delete performance
- Implement periodic cleanup system for old soft-deleted items
- Add restore methods for both nouns and verbs
- Require metadata contracts for all augmentations
- Eliminate namespace collisions with clean separation (_brainy, _augmentations, _audit)
- Optimize index performance using flattened dot-notation for O(1) lookups
- Add comprehensive augmentation safety system with type-safe access control
- Maintain full backward compatibility for existing data
- Add enterprise-grade cleanup with configurable age thresholds and batch processing

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

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

src/augmentations/neuralImport.ts

@@ -65,6 +65,10 @@ export interface NeuralImportConfig {
 export class NeuralImportAugmentation extends BaseAugmentation {
   readonly name = 'neural-import'
   readonly timing = 'before' as const  // Process data before storage
+  readonly metadata = {
+    reads: '*' as '*',  // Needs to read data for analysis
+    writes: ['_neuralProcessed', '_neuralConfidence', '_detectedEntities', '_detectedRelationships', '_neuralInsights', 'nounType', 'verbType'] as string[]
+  }  // Enriches metadata with neural analysis
   operations = ['add', 'addNoun', 'addVerb', 'all'] as ('add' | 'addNoun' | 'addVerb' | 'all')[]  // Use 'all' to catch batch operations
   readonly priority = 80  // High priority for data processing