apps/web/src/components/ChatView.tsx                   |  51 ++++++++++
 apps/web/src/components/LegacySidebar.tsx              |  55 ++++++++++-
 apps/web/src/components/Sidebar.tsx                    | 110 ++++++++++++++++++++-
 apps/web/src/routes/_chat.$environmentId.$threadId.tsx |  12 ++-
 apps/web/src/sidebarPendingFileDropStore.test.ts       | 163 ++++++++++++++++++++++++++++++++
 apps/web/src/sidebarPendingFileDropStore.ts            |  74 +++++++++++++++
 docs/user/thread-sidebar.md                            |   5 +
 7 files changed, 462 insertions(+), 8 deletions(-)