**feat: add write-only mode support and example usage**

- Introduced `writeOnly` mode in `BrainyData` allowing optimized data ingestion by skipping index loading and disabling search operations.
- Enhanced `BrainyDataConfig` to include `writeOnly` support and validate compatibility with `readOnly` mode.
- Implemented error handling for search attempts during `writeOnly` mode.
- Updated the README with detailed usage examples for database modes, including `writeOnly` and `readOnly`.
- Added `examples/write-only-mode.js` to demonstrate practical applications of the `writeOnly` mode.

**Purpose**: Optimize memory usage and startup time for data ingestion scenarios by enabling write-only mode with comprehensive documentation and examples.

README.md

@@ -598,6 +598,37 @@ await db.deleteVerb(verbId)
 
 ## Advanced Configuration
 
+### Database Modes
+
+Brainy supports special operational modes that restrict certain operations:
+
+```typescript
+import { BrainyData } from '@soulcraft/brainy'
+
+// Create and initialize the database
+const db = new BrainyData()
+await db.init()
+
+// Set the database to read-only mode (prevents write operations)
+db.setReadOnly(true)
+
+// Check if the database is in read-only mode
+const isReadOnly = db.isReadOnly() // Returns true
+
+// Set the database to write-only mode (prevents search operations)
+db.setWriteOnly(true)
+
+// Check if the database is in write-only mode
+const isWriteOnly = db.isWriteOnly() // Returns true
+
+// Reset to normal mode (allows both read and write operations)
+db.setReadOnly(false)
+db.setWriteOnly(false)
+```
+
+- **Read-Only Mode**: When enabled, prevents all write operations (add, update, delete). Useful for deployment scenarios where you want to prevent modifications to the database.
+- **Write-Only Mode**: When enabled, prevents all search operations. Useful for initial data loading or when you want to optimize for write performance.
+
 ### Embedding
 
 ```typescript