feat: sanction DM links and per-event colour coding (#13)

## Summary

- Adds resource links (appeal form, sanction logs, contact page, community invite) to all sanction DMs, separated from the sanction text by a Components v2 separator
- Adds a unique accent colour for every mod log and activity log event type, giving each action a distinct visual identity at a glance

## Changes

- `src/utils/components.ts` — Added `sanctionDmMessage` helper with two-section container (sanction text + links); added full `Colours` palette covering all sanction and activity event types; added `ColourKey` export
- `src/commands/{ban,kick,mute,softban,warn}.ts` — Updated DMs to use `sanctionDmMessage` with the appropriate colour
- `src/modules/logModAction.ts` / `logActivity.ts` — Thread `colour` parameter through to message builders
- All event and command files updated with their respective colours

✨ This PR was created with help from Hikari~ 🌸

Reviewed-on: #13
Co-authored-by: Hikari <hikari@nhcarrigan.com>
Co-committed-by: Hikari <hikari@nhcarrigan.com>

src/events/threadUpdate.ts

@@ -52,6 +52,7 @@ export const onThreadUpdate = async(
 
     await logActivity({
       client: newThread.client,
+      colour: "threadUpdated",
       emoji:  "🔄",
       fields: fields,
       title:  "Thread Updated",