release: 1.0.0-beta.56 (security hotfix)

taOS 1.0.0-beta.55

taOS 1.0.0-beta.54

taOS 1.0.0-beta.53

1.0.0-beta.52

fix: replace white tokens with shell tokens across chat components

- Replace all white/NN theme tokens with shell- tokens in MessageInput, MessageList,
  AttachmentsBar, AttachmentGallery, AttachmentLightbox, MessageEditor, MessageTombstone,
  PinBadge, PinnedMessagesPopover, ChannelSidebar, ChannelSettingsPanel, HelpPanel,
  MessageOverflowMenu, SearchPanel, SlashMenu, ThreadIndicator
- Rounded composer with attach+send, blurred header, message hover states
- Aria-labels on icon buttons preserved/supplemented
- Build green; 265/265 tests pass; grep shows no new white/NN in touched files

Merge pull request #2504 from jaylfc/dev

release: promote dev to master for 1.0.0-beta.50

Merge pull request #2366 from jaylfc/sync/dev-to-master-beta48

release: promote dev to master (v1.0.0-beta.48, sync branch)

Merge pull request #2320 from jaylfc/dev

release: promote dev to master (v1.0.0-beta.47)