fix: Windows compatibility improvements (cross-platform scripts & paths)

[steven4343]

Problem

Windows developers could not run the project out of the box:

• NODE_ENV=... syntax in npm scripts fails on Windows
• lint-staged used bash -c which requires git-bash
• Config paths used Unix-specific conventions (/tmp/, ~/)
• File paths used hardcoded / separators

Changes

• Added cross-env devDependency for cross-platform env variables
• Updated start:dev, start:debug, start:e2e, test:e2e to use cross-env NODE_ENV=...
• Removed bash -c wrapper from lint-staged config
• Changed e2e config DB path from /tmp/... to ./tmp/...
• Changed example config DB path from ~/... to ./data/...
• Replaced hardcoded / separators with path.join() in file-logger.ts

Testing

• npm install completes without native build errors on Windows
• All scripts work consistently on Windows, Linux, and macOS