activity, capabilities, chat history and the locale picker (21 -> 2)

The locale picker's labels are now AUTONYMS computed from Intl -- each language named
in its own language, so "Português europeu" reads as Portuguese whichever locale the
UI is in. That is the convention for a language picker and the useful behaviour:
somebody who cannot read the current language still has to find theirs.

CapabilityPage interpolated the capability KIND into six strings by lowercasing it in
code. "skill" does not lowercase into a Portuguese noun, so kind is a parameter now.

What is left is two strings, both deliberate: see the next commit message.

src/apps/officer-web/lib/locales.ts

@@ -6,9 +6,22 @@
  */
 export type ShippedLocale = { code: string; label: string };
 
-export const SHIPPED_LOCALES: ShippedLocale[] = [
-  { code: 'en-GB', label: 'English (UK)' },
-  { code: 'pt-PT', label: 'Português (Portugal)' },
-];
+/**
+ * The label is an AUTONYM — each language named in its own language, so "Português" reads as Portuguese
+ * whichever locale the UI is currently in. That is the convention for a language picker and it is the
+ * useful behaviour: somebody who cannot read the current language still has to find theirs.
+ *
+ * Computed rather than written down, for the same reason the spoken-language list is (see Languages.tsx):
+ * `Intl` already knows every language's name in every locale, including its own.
+ */
+const autonym = (code: string): string => {
+  const name = new Intl.DisplayNames([code], { type: 'language', fallback: 'code' }).of(code) ?? code;
+  return name.charAt(0).toUpperCase() + name.slice(1);
+};
+
+export const SHIPPED_LOCALES: ShippedLocale[] = ['en-GB', 'pt-PT'].map((code) => ({
+  code,
+  label: autonym(code),
+}));
 
 export const FALLBACK_LOCALE = 'en-GB';