Add TypeScript dev tooling and fix typings

Add TypeScript / linting devDependencies and enable DOM/Node types in
tsconfig. Update code and tests to satisfy stricter type checking:
- parse URL params into temp strings before parseInt in logs route
- improve tags error detection in MCP memories tools
- remove T4 guard in sqlite store and drop related test assertion
- add non-null assertions and casts in multiple tests to avoid
  undefined access errors

These changes prepare the repo for TypeScript 6 and stricter linting
rules.