- Mail list: title and subject font text-xs -> text-sm
- Remove Termin (create-event) toolbar button
- Rename Flagge -> Markierung with select dropdown (star, flag, bookmark, important, question)
- Backend: add flag_type column to Mail model + migration 0006
- Backend: flag_type in MailFlagsUpdate schema, update_flags route, mail_to_response
- Frontend: flag_type in Mail interface, FlagUpdatePayload, MailList symbol display
- MailFolderTree: reduce padding/gap ~25% (py-2→py-1, gap-2→gap-1.5)
- MailList: text-sm→text-xs for from and subject lines
- ResizablePanel: use DOM ref for width during drag instead of React state
- No re-renders during drag, only single setWidth on mouseup
- panelRef on outer div, contentRef on inner div
- pointer-events:none on content during drag
- contain:strict on content area
- Fix sync error: backend returns {synced, error?} not {success, synced_count}; frontend now checks error field
- Decode MIME encoded-words (=?UTF-8?Q?...?=) in backend during IMAP sync for subject/from/to/cc headers
- Add frontend decodeMimeHeader() utility for already-stored encoded subjects (MailList + MailDetail)
- Make pagination sticky at bottom of mail list (flex-col h-full, ul scrolls, pagination flex-shrink-0)
- Make pagination compact: smaller padding (px-1.5 py-0.5), text-xs, smaller icons, tighter spacing
- Fix FlagUpdatePayload field names to match backend schema (is_seen/is_flagged)
- Replace dangerouslySetInnerHTML with sandboxed iframe (srcDoc, sandbox="")
- Add bulk mark read/unread with checkbox selection in MailList
- Add floating bulk action bar in Mail.tsx
- Add imap_sync_mail_flags() to push Seen/Flagged flags to IMAP server
- Call IMAP flag sync in PATCH /flags endpoint
- Add i18n keys for bulk actions (de/en)