[Fix] Discord review resolutions appear as full-size text

[roomote-community]

​Created by Roomote. Follow up by mentioning @roomote, in the web UI, or in Discord.

What changed

Discord PR review action resolutions now use Discord's -# subtext syntax when replacing the action buttons, including notifications whose original content is empty. Message truncation accounts for the formatting prefix, and focused coverage verifies the auto-resolve copy, empty-content behavior, and maximum message length.

Why this change was made

Discord displayed the action resolution as full-size body text, while Slack presents the equivalent status as compact context. This makes the two integration experiences visually consistent.

Impact

PR review action confirmations in Discord render as smaller, quieter status text beneath the preserved review notification, or by themselves when there is no notification body, without exceeding Discord's message limit.

[roomote-community]

No issues outstanding. See task

• apps/api/src/handlers/discord/pr-review-action.ts:47 Empty Discord notification content bypasses the new subtext prefix.

_{Reviewed 400e53e}