feat(android): settings live on the device, dark theme, and the app is called Coffre

URL and token are no longer constants. They sit in settings.bin, sealed with the no-auth Keystore AES key - deliberately weaker than the vault: they must be readable to rebuild a vault that no longer exists, and a bearer token only opens ENCRYPTED data, worthless without the sync password that stays in the guarded vault. Retyping 64 hex characters after every cache purge was the real risk: the risk of writing them down elsewhere. They are saved only after a fetch that worked - proven settings, not typed ones.

The token and sync password moved to the gitignored local include, as first-run defaults only. Tracked source now carries no secret, and leaving them empty is a viable configuration: the app asks.

Theme: Delphi's Dark.style, copied into the repo and linked as a resource rather than deployed as a file - this project's deployment puts nothing beside the app, which is the same hole that forces the manifest and dex staging. A failure to load is never fatal; the default look is ugly but works.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

android-client/PMA.Theme.pas

@@ -0,0 +1,43 @@
+unit PMA.Theme;
+{
+  Thème sombre, chargé depuis une ressource embarquée.
+
+  POURQUOI UNE RESSOURCE ET NON UN FICHIER : le mecanisme de deploiement de ce
+  projet ne pose aucun fichier a cote de l'application - c'est le meme trou qui
+  oblige a mettre en place le manifeste et les .dex a la main. Une ressource
+  liee dans le .so ne depend de rien : elle est la ou n'est pas, et elle est la.
+
+  Le style vient de Dark.style, livre avec Delphi, recopie dans le depot pour
+  que la compilation ne dependre pas d'un chemin d'installation.
+
+  Un echec ici n'est jamais fatal : sans style, l'application garde l'apparence
+  par defaut. Elle est laide, elle fonctionne.
+}
+
+interface
+
+/// A appeler une fois, avant la creation de la forme.
+procedure ApplyDarkTheme;
+
+implementation
+
+uses
+  System.SysUtils, System.Types, System.Classes, FMX.Styles, FMX.Types;
+
+{$R 'theme\theme.res' 'theme\theme.rc'}
+
+procedure ApplyDarkTheme;
+var
+  LStyle: TFmxObject;
+begin
+  try
+    // La lecture appartient a TStyleStreaming, l'application a TStyleManager.
+    LStyle := TStyleStreaming.LoadFromResource(HInstance, 'PMDARKSTYLE', RT_RCDATA);
+    if LStyle <> nil then
+      TStyleManager.SetStyle(LStyle);
+  except
+    // Rien : l'apparence par defaut reste utilisable.
+  end;
+end;
+
+end.