[Migration] Convert Utility Functions to TS

[fabiovincenzi]

Goal

Convert helper modules to TypeScript as they have minimal dependencies.

Tasks

• Identify and convert utility files to TypeScript
• Define TypeScript interfaces for shared data structures

Notes:
These files are usually self-contained and easy to convert.

[jescalada]

I got two PRs out for what I consider "utility" modules. I think converting on a per-module basis is more reasonable so we don't miss any files along the way.

db module: #27
config module: #31

Everything else seems to be coupled to other modules. Proxy logic is in proxy, API logic is in service, and UI (rather large) is in ui.