fix(i18n): one sentence each for the read-failure lines

The ended-session and spent-budget lines each ran to two sentences; the
action sits on the button, so each is one sentence now. The sign-in
label's key is common.signIn, matching what it says. The French strings
added in this release use vous like the rest of the bundle, and the
Korean sleep-score gap labels take the polite form the bundle uses.

src/hooks/use-read-failure.ts

@@ -45,7 +45,7 @@ export function useReadFailure(
         kind: "unauthenticated",
         message: t("common.sessionEnded"),
         action: {
-          label: t("common.signInAgain"),
+          label: t("common.signIn"),
           onClick: () => window.location.assign(signInHref()),
           kind: "signIn",
         },