Mail · Writing: the composer, recipients that suggest, a signature, send later

MailComposer writes a message: To, and Cc and Bcc once asked for, as
tag fields that suggest contacts and mark what is not an address; the
subject and the words; the files, each with a way off; the signature
under the words. Send wakes once there is someone to send to and every
address is one; it hands over the draft now or at a time, and Discard
lets it go. A new start from the owner begins the draft over.

forms::TagInput now suggests: the rows that hold the typed words float
under it through the list Combobox uses; Up, Down and Enter pick, and
Escape sets them aside. RecipientInput points to it. ScheduleSend
offers tomorrow morning, tomorrow afternoon, Monday morning, or a day
and hour picked in a dialog. SignatureEditor writes the lines and shows
how they sit under a message; it tells the owner's echo from a new
signature, so the caret stays.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

TASKS.md

@@ -104,7 +104,7 @@ Per-component lines live in `tasks/`. Tags there:
 - [x] T28d Messaging · Calls
 - [x] T28e Messaging · Stickers and GIFs
 - [x] T29a Mail · Boxes and lists
-- [ ] T29b Mail · Reading
+- [x] T29b Mail · Reading
 - [ ] T29c Mail · Writing
 - [ ] T29d Mail · Sorting
 - [ ] T30 Calendar
@@ -344,3 +344,5 @@ Per-component lines live in `tasks/`. Tags there:
 | T28e | 2 | PASS | |
 | T29a | 1 | FAIL | Space on a focused star also toggled the list's selection |
 | T29a | 2 | PASS | |
+| T29b | 1 | FAIL | a folded message lost focus as it opened; a long name beside a long date ran past a 280px fold |
+| T29b | 2 | PASS | |