Add Discord slash command integration

[pntech20]

Summary

• adds a minimal /sanctifier Discord bot with explain, latest, and status subcommands
• includes command registration, bot runtime, finding-code explanations, latest-report formatting, and endpoint status checks
• documents setup, environment variables, and deployment notes for staging or production servers

Checks

• npm test
• node --check src/commands.js; node --check src/bot.js; node --check src/register-commands.js
• git diff --check

Closes #850

[vercel]

@pntech20 is attempting to deploy a commit to the gbangbolaoluwagbemiga's projects Team on Vercel.

A member of the Team first needs to authorize it.

[Gbangbolaoluwagbemiga]

Fix conflicts @pntech20

[pntech20]

Moved the Node-specific README and env example off the conflicting paths and pushed the updated branch.