build the app, and ship it on Linux and Windows as well as macOS

The client itself: the sync engine and mirror, the Gmail and IMAP providers,
the screener, the three boxes and two piles, compose and send, the sanitiser
and tracker stripping, contacts, clips, backup, notifications and the guide.

The pipeline that ships it. Three runners now build in parallel and the
publish gate wants all four platform keys in latest.json before a release
leaves draft. Linux gets two more packages Tauri does not build: a flatpak
repackaged from the deb against GNOME 48, and a Nix package that relinks the
deb against nixpkgs so it runs as a native Wayland client rather than through
Xwayland. CI runs the Rust suite on all three desktops rather than on Linux
alone, and rebuilds the flatpak manifest on every push to main.

Two things that were only ever exercised on macOS and were wrong everywhere
else. The menu bar was built by adjusting the submenus macOS is given, so on
a platform whose default menu has no File or View the new File menu landed
after Edit, Check for Updates landed nowhere, and the three places and the
reading pane had no menu at all. The deb declared libwebkit2gtk-4.1-0 and
libgtk-3-0 twice, because tauri.conf.json named the dependencies Tauri
already emits.

The updater key exists now, so releases can sign their artifacts.

src-tauri/fixtures/outlook-reply.eml

@@ -0,0 +1,46 @@
+Return-Path: <[email protected]>
+MIME-Version: 1.0
+Date: Tue, 1 Sep 2026 16:41:09 +0100
+Message-ID: <AM0PR07MB5218F1C0D9E2A4E1B@AM0PR07MB5218.eurprd07.prod.outlook.com>
+In-Reply-To: <[email protected]>
+References: <[email protected]>
+Subject: RE: The lease, clause 14
+From: "Young, Russell" <[email protected]>
+To: Priyanshu Jain <[email protected]>
+Content-Type: multipart/alternative; boundary="_000_AM0PR07MB5218_"
+
+--_000_AM0PR07MB5218_
+Content-Type: text/plain; charset="utf-8"
+Content-Transfer-Encoding: quoted-printable
+
+Clause 14 is the standard form. I would not sign it as drafted.
+
+Russell
+
+-----Original Message-----
+From: Priyanshu Jain <[email protected]>
+Sent: Tuesday, 1 September 2026 12:00
+To: Young, Russell <[email protected]>
+Subject: The lease, clause 14
+
+Russell, is clause 14 negotiable or is it the landlord's standard form?
+
+--_000_AM0PR07MB5218_
+Content-Type: text/html; charset="utf-8"
+Content-Transfer-Encoding: quoted-printable
+
+<html><body>
+<p>Clause 14 is the standard form. I would not sign it as drafted.</p>
+<p>Russell</p>
+<div style=3D"border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0cm =
+0cm 0cm">
+<hr>
+<div id=3D"divRplyFwdMsg">
+<p><b>From:</b> Priyanshu Jain &lt;[email protected]&gt;<br>
+<b>Sent:</b> Tuesday, 1 September 2026 12:00<br>
+<b>Subject:</b> The lease, clause 14</p>
+<p>Russell, is clause 14 negotiable or is it the landlord's standard form?</p>
+</div></div>
+</body></html>
+
+--_000_AM0PR07MB5218_--