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/fr.ts

@@ -853,6 +853,15 @@ 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}.": "Cette traduction a été générée par une IA et n'a pas été relue par une personne de langue maternelle française ; elle est donc marquée Beta jusqu'à validation. Tout ce qui sonne faux mérite d'être signalé — {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} est la palette de {site}, et celle d'un nouveau compte. C'est un thème sombre : il compte donc comme sombre partout où cela importe, et la couleur d'accentuation ci-dessous s'y applique toujours.",
     "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 version de ihasmail est la date du commit à partir duquel elle a été construite, suivie de l'origine de ce commit : {example} provient d'un commit daté du 30 août 2026 arrivé via la pull request 129. Un commit qui n'est pas passé par là porte à la place son SHA court — {sha}. La version ne dit délibérément rien de Stalwart ; ce dont cette build a besoin du serveur figure à la ligne ci-dessus.",
+
+    // ── Composer status, calendar title ────────────────────────────────
+    "New message": "Nouveau message",
+    "Sending…": "Envoi…",
+    "Saving…": "Enregistrement…",
+    "Error": "Erreur",
+    "Saved {when}": "Enregistré {when}",
+    "Unsaved": "Non enregistré",
+    "Agenda from {date}": "Agenda à partir du {date}",
   },
   plurals: {
     "{n} messages": { one: "{n} message", other: "{n} messages" },