feat(webmail): a better reader and a drawn logo

The mark is rebuilt as a lambda of two square-cut strokes of one weight, joined
without a seam, on a flat ultramarine tile with continuous corners: the rounded
strokes and the gradient are gone. A message written plainly is now drawn in the
app's own colours instead of a white slab, with text too dark for the ground
lifted and white backdrops cleared; a designed one (newsletter, receipt) keeps
its white sheet. A reply's quoted history folds behind a button. A narrower
reading column, a larger title, and a way to see a plain message as sent.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

services/webmail/messages/en.json

@@ -586,5 +586,9 @@
     "hintClose": "close",
     "open": "Command menu",
     "signOut": "Sign out"
+  },
+  "viewer": {
+    "asSent": "View as sent",
+    "adapt": "Match the theme"
   }
 }

services/webmail/messages/es.json

@@ -586,5 +586,9 @@
     "hintClose": "cerrar",
     "open": "Menú de comandos",
     "signOut": "Cerrar sesión"
+  },
+  "viewer": {
+    "asSent": "Ver como se envió",
+    "adapt": "Adaptar al tema"
   }
 }

services/webmail/messages/pt-BR.json

@@ -586,5 +586,9 @@
     "hintClose": "fechar",
     "open": "Menu de comandos",
     "signOut": "Sair"
+  },
+  "viewer": {
+    "asSent": "Ver como enviado",
+    "adapt": "Adaptar ao tema"
   }
 }