Latch v0.31.0: Private ticket conversation exports

Latch 0.31.0: Private ticket exports

• Add /ticket transcript for private text or JSON downloads of 1 to 100 recent messages. Defaults: 50 messages, text, current ticket channel.
• Recheck current human membership, support/admin privileges and effective channel read permissions. Guests cannot export conversations.
• Preserve exact numeric message ordering and include normalized authors, IDs, timestamps, replies, returned text, attachment links and embed text.
• Send one bounded multipart attachment on the private response without storing local transcripts or copying conversation data into backups.
• Reject oversize exports instead of truncating them. Document content-intent limits and omitted data.

Verification: 866 tests passed, including 32 new export/upload regressions, with enforced coverage floors. All 27 isolated runtime checks passed. The reference lists 203 command paths across 25 roots. Windows/Linux Node 22/24 and container CI passed on the exact merged commit.

Upgrade: re-register commands. No new store format is introduced. Continue complete stopped-process backups; existing ticket format 2, economy format 3 and community format 3 need compatible backups when rolling back to older releases.

Export limits: recent-message snapshots only, not full archives. Older/deleted messages, attachment bytes, embed images, reactions, polls, stickers and components are excluded. Message Content access can affect returned text, embeds and attachments. Links can expire. Keep downloaded private conversation data private. See docs/TICKET-TRANSCRIPTS.md.

Free MIT-licensed source prerelease. Actual Discord file uploads, content access and full live acceptance remain unverified. Music, advanced antinuke and complete competitor parity remain unfinished.

CI: https://github.com/informent/Latch/actions/runs/38184545442