feat: implement always-adaptive caching with getCacheStats monitoring

Replaces lazy mode concept with always-adaptive caching strategy:

- Rename getLazyModeStats() → getCacheStats() with enhanced metrics
- Change lazyModeEnabled boolean → cachingStrategy enum ('preloaded' | 'on-demand')
- Update preloading threshold from 30% to 80% for better cache utilization
- Add comprehensive production monitoring and diagnostics
- Add memory detection for containers (Docker/K8s cgroups v1/v2)
- Add adaptive memory sizing from 2GB to 128GB+ systems

Breaking changes: None (backward compatible, deprecated lazy option ignored)

New APIs:
- getCacheStats(): Comprehensive cache performance statistics
- cachingStrategy field: Transparent strategy reporting
- Enhanced fairness metrics and memory pressure monitoring

Documentation:
- Add migration guide for v3.36.0
- Add operations/capacity-planning.md for enterprise deployments
- Update all examples and troubleshooting guides
- Rename monitor-lazy-mode.ts → monitor-cache-performance.ts

docs/API_REFERENCE.md

@@ -26,7 +26,7 @@ import { Brainy, NounType, VerbType } from '@soulcraft/brainy'
 
 // Initialize
 const brain = new Brainy({
-  storage: { type: 'memory' },
+  storage: { type: 'filesystem', path: './brainy-data' },
   model: { type: 'fast', precision: 'Q8' }
 })
 await brain.init()
@@ -554,16 +554,7 @@ Brainy supports multiple storage backends for different deployment scenarios.
 
 ### Storage Types
 
-#### Memory Storage (Default)
-Fast in-memory storage, ideal for testing and development.
-
-```typescript
-const brain = new Brainy({
-  storage: { type: 'memory' }
-})
-```
-
-#### File System Storage
+#### File System Storage (Recommended for Development)
 Persistent local storage using the filesystem.
 
 ```typescript