Translate the labels the extractor could not see

Three places built user-visible English out of expressions rather than
writing it as JSX text, so the extraction codemod never found them and
they stayed English in all nine languages — including the five that have
been in production for weeks.

The calendar view switcher was the worst of them: it spelled its labels
as `v[0].toUpperCase() + v.slice(1)`, which is correct English and
untranslatable anywhere else. Day, Week, Month and Agenda were already in
every catalogue, sitting unused, because the buttons never asked for
them. They now come from a Record<View, () => string>, so TypeScript
makes the map exhaustive and adding a view forces adding its label. The
labels are functions rather than values: a module-level object would
capture whichever language happened to load first and keep it.

The other two needed new source strings, added to all nine catalogues:
the composer's title for an untitled draft ("New message"), its status
line ("Sending…", "Saving…", "Error", "Saved {when}", "Unsaved"), and the
agenda view's own title ("Agenda from {date}").

This is not the whole of it. A sweep for the same shape — template
literals, toast arguments, and dialog props rather than JSX text — turns
up roughly a hundred more strings, mostly toasts and confirmation
dialogs. Those are a second extraction pass rather than a fix, and are
left for one.

web/src/locales/es.ts

@@ -848,6 +848,15 @@ export const catalog: Catalog = {
     "This translation was generated by AI and has not been checked by a native speaker, so it is marked Beta until somebody who speaks it signs it off. Anything that reads wrongly is worth reporting — {report}.": "Esta traducción la ha generado una IA y no la ha revisado ninguna persona de habla nativa, así que está marcada como Beta hasta que alguien la dé por buena. Todo lo que suene mal merece un aviso: {report}.",
     "{name} is the palette from {site}, and what a new account starts on. It is a dark theme, so it counts as dark wherever that matters, and the accent colour below still applies on top of it.": "{name} es la paleta de {site}, y con la que empieza una cuenta nueva. Es un tema oscuro, así que cuenta como oscuro allí donde importa, y el color de acento de abajo se sigue aplicando encima.",
     "ihasmail's own version is the date of the commit it was built from, followed by where that commit came from: {example} was built from a commit dated the 30th of August 2026 that arrived through pull request 129. A commit that did not come through one carries its short SHA instead — {sha}. The version deliberately says nothing about Stalwart; what this build needs from the server is the line above.": "La versión de ihasmail es la fecha del commit a partir del cual se compiló, seguida de su procedencia: {example} se compiló a partir de un commit del 30 de agosto de 2026 que llegó mediante la pull request 129. Un commit que no llegó por esa vía lleva en su lugar su SHA corto: {sha}. La versión no dice nada sobre Stalwart a propósito; lo que esta compilación necesita del servidor está en la línea de arriba.",
+
+    // ── Composer status, calendar title ────────────────────────────────
+    "New message": "Mensaje nuevo",
+    "Sending…": "Enviando…",
+    "Saving…": "Guardando…",
+    "Error": "Error",
+    "Saved {when}": "Guardado {when}",
+    "Unsaved": "Sin guardar",
+    "Agenda from {date}": "Agenda desde {date}",
   },
   plurals: {
     "{n} messages": { one: "{n} mensaje", other: "{n} mensajes" },