**docs: remove outdated statistics-related documentation and add standards**

- **Removed Files**:
  - Deleted outdated statistics documentation files (`statistics.md`, `statistics-flush-solution.md`, `statistics-summary.md`) to clean up the repository and avoid confusion.

- **Added Standards**:
  - Introduced `DOCUMENTATION_STANDARDS.md` to outline naming conventions and troubleshooting practices for more consistent and maintainable project documentation.

- **Tests**:
  - Added a new test file `edge-cases.test.ts` to verify handling of edge cases, ensuring robust behavior against boundary values and invalid inputs.

**Purpose**: Cleans up deprecated documentation while introducing concrete standards for maintaining and updating documentation. Enhances test coverage for unusual or boundary inputs, improving overall system resilience.

tests/database-operations.test.ts

@@ -1,5 +1,5 @@
 import { describe, it, expect } from 'vitest'
-import { BrainyData } from '../dist/brainyData.js'
+import { BrainyData } from '../dist/unified.js'
 
 describe('Database Operations', () => {
   let db: BrainyData
@@ -61,4 +61,4 @@ describe('Database Operations', () => {
     // Clean up
     await db.delete(id)
   })
-})
+})