refactor: move any hardcoded variables to constants

[alepouna]

Description

EXTENSIVE TESTING REQUIRED!

• Moves all hardcoded variables (e.g. embed colors, channels IDs, etc.) to a new file 'constants.ts' for better organization and preventing miss-matches from forgotten variables.
• Command files linting (removes unused vars)
• Add node types to package.json as it was missing

[alepouna]

gonna wait for the other 2 PRs to merge to also patch them up