fix(compose): default to quoting below, and focus the body on a reply

The previous commit fixed the cursor within each quote_position branch and
the user still saw the old layout, because the branches were already right:
what was wrong was the DEFAULT. quote_position shipped as `above`, and the
layout asked for is exactly what `below` already produced, a blank line at
the top with the quote underneath.

So the default flips, along with the fallback for a malformed value and the
warning naming it. Nothing needs an Upgrading note: compose has not been
released, so no config in the wild sets this.

Focus goes to the body whenever To: is already filled, which a Reply and a
Forward always are. The form's first widget took it otherwise, so the user
had to click into the editor before typing. A New message keeps the default,
since an empty To: is genuinely the first thing to fill in.

The focus test asserts on the window's focusWidget() rather than on
QWidget::hasFocus(): an unshown window is never active, so hasFocus() reads
false whatever the code does and would fail against a correct fix. Both
directions are mutation-checked, since focusing unconditionally passes the
reply case while breaking the new-message one.

1 files changed, 4 insertions, 2 deletions

diff --git a/README.md b/README.md
index 75f9cbe..c80323f 100644
--- a/README.md
+++ b/README.md
@@ -262,8 +262,10 @@ drafts = Drafts
 ; about the sender's software rather than a guess about their taste.
 send_html = true
 
-; Where the quoted original goes in a reply: above or below.
-quote_position = above
+; Where the quoted original goes relative to your reply: below (the default,
+; you type at the top and the quote follows) or above (bottom-posting, the
+; quote first and the cursor after it).
+quote_position = below
 
 ; How long the send popup counts down before the command runs, in
 ; milliseconds. This is the window in which Undo can still stop it; 0 skips