Open the composer full screen, as a setting (#401) (#404)

Settings > General > Composing has a new switch, "Open the composer full
screen". With it on, every new composer, whether a new message, reply,
forward or reopened draft, starts maximized. Restore still shrinks it to
a window. A draft put back after an undone or failed send keeps the size
it had. It's off by default, and on a phone, where the composer already
fills the screen, it changes nothing.

One new string, translated in all nine catalogs. The count falling back
to English stays at 16 in every language.

Fixes #401

Co-authored-by: Claude Opus 5 (1M context) <[email protected]>

web/src/store/compose.ts

@@ -137,7 +137,7 @@ function blankDraft(init: Partial<Draft> = {}): Draft {
     showBcc: false,
     showReplyTo: false,
     minimized: false,
-    maximized: false,
+    maximized: s.composeMaximized,
     dirty: false,
     savedAt: null,
     saving: false,