refactor(l10n): default strings to all targets

Most strings were imported with a platform-specific `targets` (usually
apple-only) just because that's where they happen to be used today. Drop the
restriction so they default to all targets and are available to KMP too; only
the four literal `%@…` format-composition keys stay apple-only.

Also fix the placeholder parser to tolerate C length modifiers (`%lld`), and
give progress_sending_to_count a proper int arg so it emits `%1$d` on both
platforms instead of a literal `%lld`.

localization/src/lib/placeholders.ts

@@ -60,8 +60,9 @@ export interface ParsedString {
   args: Arg[];
 }
 
-// Matches an escaped literal `%%` or a printf specifier (positional or bare).
-const CONV = /%%|%(?:(\d+)\$)?([@sdif])/g;
+// Matches an escaped literal `%%` or a printf specifier (positional or bare),
+// tolerating C length modifiers like `%lld` / `%ld` on the integer forms.
+const CONV = /%%|%(?:(\d+)\$)?l{0,2}([@sdif])/g;
 
 function typeForConv(conv: string): ArgType {
   if (conv === "@" || conv === "s") return "string";