fix(memory): convert to modern TypeScript SDK APIs (#3015)

* fix(memory): convert to modern TypeScript SDK APIs

Convert the memory server to use the modern McpServer API instead of
the low-level Server API.

Key changes:
- Replace Server with McpServer from @modelcontextprotocol/sdk/server/mcp.js
- Convert all 9 tools to use registerTool() instead of manual request handlers
- Create reusable Zod schemas for Entity and Relation types
- Use Zod schemas directly in inputSchema/outputSchema
- Add structuredContent to all tool responses
- Fix type literals to use 'as const' assertions

The modern API provides:
- Less boilerplate code (removed ~200 lines of schema definitions)
- Better type safety with Zod
- More declarative tool registration
- Cleaner, more maintainable code

* fix: exclude test files from TypeScript build

Add exclude for test files and vitest.config.ts to tsconfig

Author: domdomegg