feat(android): show attachments, without carrying their bytes

One attachment took the cache from 13 to 174 KB: the content travels base64 in the snapshot and is decrypted in memory with the rest. TVault reads name, type and size and DROPS content_b64 - holding it for the whole vault while nothing displays it would be paying for nothing.

The detail now says a document exists. Saving it is what remains, and what blocks that is not code but where a file lands on Android 10+. When that is settled, the content re-reads from the raw JSON.

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

mainApk.pas

@@ -516,6 +516,16 @@ begin
   OnSearchChanged(nil);
 end;
 
+function HumanSize(ABytes: Int64): string;
+begin
+  if ABytes >= 1024 * 1024 then
+    Result := Format('%.1f Mo', [ABytes / (1024 * 1024)])
+  else if ABytes >= 1024 then
+    Result := Format('%.0f Ko', [ABytes / 1024])
+  else
+    Result := Format('%d o', [ABytes]);
+end;
+
 procedure TForm8.ClearDetailRows;
 var
   LRow: TLayout;
@@ -573,6 +583,13 @@ begin
     if LMeta <> '' then LMeta := LMeta + '  -  ';
     LMeta := LMeta + FCurrent.Tags;
   end;
+  // Les pieces jointes ne sont pas encore enregistrables sur le telephone,
+  // mais taire leur existence serait pire : on saurait sur le poste qu'une
+  // entree porte un document, et pas ici.
+  for I := 0 to High(FCurrent.Attachments) do
+    Add('Piece jointe', FCurrent.Attachments[I].FileName + '   ' +
+        HumanSize(FCurrent.Attachments[I].SizeBytes), False);
+
   Add('Dossier / etiquettes', LMeta, False);
   // Le sous-type n'existe que pour les modeles (carte, cle SSH, serveur...) ;
   // Add ignore une valeur vide, donc rien a tester ici.