docs: close out compose and send, and drop the v1/v2 split

Task 13 of item 123, the documentation that was left when the code was
finished.

The README claimed "sending is not implemented. Compose, reply, forward and
send are planned for v2 and need a companion send script that does not exist
yet", which had been false for three days. It also documented none of
`trash`, `send_command` or the `[compose]` section: `trash` has been effectively
mandatory since item 103 and its absence breaks Delete, so a user reading only
the README could not configure a working install. Both are item 122, which
closes with this.

Every default in the new [compose] block was read out of config.h rather than
from the prose around it, which was worth doing: send_html defaults to TRUE
and the first draft of this documented it as false, and the key is
autosave_interval_ms rather than the autosave_delay_ms that reads more
naturally.

The v1/v2 language is retired rather than updated. The project follows semver
on its user-visible surface and those labels described a scope split that
stopped being true when compose shipped. CLAUDE.md says so explicitly rather
than deleting the sentence, since the older spec and plan documents still use
the phrase and are historical records: read it there as "before compose".

CLAUDE.md's architecture diagram listed none of the compose units. It does
now, and it distinguishes the classes from the namespaces, because most of
them are namespaces of free functions over values: the markdown, the MIME
assembly and the account-picking are all testable without a widget. There is
no FormatToolbar class, which the first draft of this diagram invented, and
that is the exact mistake the paragraph under it already warns about for
QueryBar and AttachmentBar.

Also records item 148 from the notes: Ctrl+W does not close the composer.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Q2koFevoSxTLhfexJTZWQd

1 files changed, 29 insertions, 6 deletions

diff --git a/CLAUDE.md b/CLAUDE.md
index b065741..031b3d2 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -64,10 +64,19 @@ MainWindow                         NotmuchWorker
  │   ONE column of cards; CardDelegate paints each whole, from CardLayout
  └ MessageView (header QLabel, QWebEngineView, attachment bar, TagStrip)
 
+ComposeWindow (its own top-level window, one per message being written)
+ ├ MarkdownFormat (namespace: what the formatting buttons do to a selection)
+ ├ MarkdownRenderer (namespace, cmark-gfm)   MessageBuilder (namespace, GMime)
+ ├ MessageSender (QProcess, the per-account send_command on stdin)
+ └ SendDialog (the undo countdown)   DraftStore (autosave to the drafts folder)
+
+ComposeContext (a struct: what a Reply or Forward inherits)
+ComposeContextBuilder (namespace: fills one, and picks the account)
 CardLayout (pure geometry, no painting)
 SearchTerm (pure query strings, no widget)
 Config (INI)   KeyMap   MailSync (QProcess)   MimeParser (GMime)
 SyncMonitor (/proc/locks)   TagColors   QueryCompleter   ThreadCidMap
+MaildirName (fresh Maildir filenames)
 ```
 
 The query row and the message-pane header are **built inline in `MainWindow` and
@@ -75,11 +84,20 @@ The query row and the message-pane header are **built inline in `MainWindow` and
 listed `QueryBar`, `SavedQueryBar`, `HeaderWidget` and `AttachmentBar`; none of
 those types have ever existed, and looking for them wastes a search. The widget
 classes that do exist are `MessageView`, `ThreadListView`, `TagStrip`,
-`TagDialog`, `MessageDetailsDialog`, `RowStyleDelegate` and `CardDelegate`;
-`TagChip` is a namespace of painting helpers, not a widget, `SearchTerm` is a
-namespace of query builders, and `ThreadCidMap`, `CardLayout`, `SearchOffer`
-and `HeaderRow` are structs. `SubjectDelegate` existed until item 53 and is
-gone.
+`TagDialog`, `MessageDetailsDialog`, `RowStyleDelegate`, `CardDelegate`,
+`ComposeWindow`, `SendDialog` and `BusyIndicator`; `TagChip` is a namespace of
+painting helpers, not a widget, `SearchTerm` is a namespace of query builders,
+and `ThreadCidMap`, `CardLayout`, `SearchOffer` and `HeaderRow` are structs.
+`SubjectDelegate` existed until item 53 and is gone.
+
+**The compose units are mostly NAMESPACES, and the same warning applies to
+them.** `MarkdownRenderer`, `MarkdownFormat`, `MessageBuilder`,
+`ComposeContextBuilder`, `DraftStore` and `MaildirName` are namespaces of free
+functions over values, deliberately, so the markdown, the MIME assembly and
+the account-picking are all testable without a widget. `MessageSender` IS a
+QObject, because it owns a `QProcess`. There is no `FormatToolbar` class: the
+composer's formatting row is built inline in `ComposeWindow` and asks
+`MarkdownFormat` what each button does to the selection.
 
 **`MessageDetailsDialog` was a `QPlainTextEdit` inside `MessageView` until item
 85.** It is rows now so each value can carry its own context menu, and its
@@ -925,7 +943,12 @@ test" position — it is the only code that writes to a notmuch index.
 Work goes directly on `master`, no PR flow. Commits must be GPG-signed (`git commit -S`).
 `HANDOFF.md` is local-only and gitignored; never stage or commit it.
 
-v1 is read-and-organize only. Compose and send are v2.
+**There is no "v1" and no "v2".** The project follows semver on its
+user-visible surface, and those labels described a scope split that stopped
+being true when compose and send shipped. Reading, organizing and sending are
+all part of the application now. The phrase survives in the older spec and
+plan documents, which are historical records and are not being rewritten; read
+it there as "before compose" and "after compose".
 
 ## Cutting a release