Add Swahili (sw) locale

Standard / Kiswahili sanifu (East African Standard) — the variety
used in BBC Swahili / VOA Swahili / DW Kiswahili news coverage,
intelligible across Tanzania, Kenya, Uganda, Rwanda, and eastern DRC.
Register: formal-conversational, not bureaucratic, not academic.

Reaches the WLC governance roster's East African leadership (Rwanda,
DRC, Burundi, and the broader ~230M-speaker activist audience).

Key choices:
- pochi for crypto wallet (modern Swahili tech vocab)
- mfadhili / wafadhili for donor(s), mwanaharakati / wanaharakati for
  activist(s), mchango / michango for donation(s), kampeni for campaign
- relei (transliteration) for Nostr relay
- malipo ya kimya for silent payments, iliyogawanywa for decentralized,
  inastahimili udhibiti for censorship-resistant
- Polite 2nd person wewe; m-/wa- and n-/n- noun classes used
  consistently for actor/wallet concord
- heroTagline avoids the orphan-period bug: trailing period sits
  inside <0>...</0> as in the English source

Sub-agent flagged several judgment calls (above-ground activism,
bleeding-edge, push notifications, honeypot metaphor) where the
English idiom doesn't carry across cleanly — these are v1 choices
that East African native speakers may want to refine. Treat this
locale as 'shippable v1, expect refinement from user feedback', same
quality bar as the other African / South-Asian locales we've shipped.

Key parity verified: 1677 leaves, same as en.json, zero missing or
extra, all {{placeholders}} and <N>markup</N> tokens preserved.

src/i18n.ts

@@ -14,6 +14,7 @@ import ps from './locales/ps.json';
 import pt from './locales/pt.json';
 import ru from './locales/ru.json';
 import sn from './locales/sn.json';
+import sw from './locales/sw.json';
 import tr from './locales/tr.json';
 import zh from './locales/zh.json';
 import zhHant from './locales/zh-Hant.json';
@@ -49,6 +50,7 @@ export const SUPPORTED_LANGUAGES: SupportedLanguage[] = [
   { code: 'ps', nativeName: 'پښتو' },
   { code: 'km', nativeName: 'ភាសាខ្មែរ' },
   { code: 'sn', nativeName: 'ChiShona' },
+  { code: 'sw', nativeName: 'Kiswahili' },
   { code: 'zh', nativeName: '简体中文' },
   { code: 'zh-Hant', nativeName: '繁體中文' },
 ];
@@ -89,6 +91,7 @@ i18n
       pt: { translation: pt },
       ru: { translation: ru },
       sn: { translation: sn },
+      sw: { translation: sw },
       tr: { translation: tr },
       zh: { translation: zh },
       // Traditional Chinese is registered under three codes pointing at the