Phase 002: rebrand to hermes-ui and consolidate i18n to zh/en

Removes the ekko / hermes-web-ui branding from the whole tree and drops
eight locale files, so the project presents one name and one language pair.

Data compatibility is deliberate, not accidental: DB filenames, the JWT
audience, and skill manifest ownership all still recognise their pre-rename
values so existing deployments under ~/.hermes-web-ui keep working without a
re-login or a re-injection.

scripts/harness-check.mjs now scans for the legacy strings and fails the
build on any new occurrence, with an explicit allow-list (and reasons) for
the compatibility paths that must keep them.

tests/client/i18n-coverage.test.ts

@@ -6,14 +6,6 @@ import { changelog } from '@/data/changelog'
 import { messages, supportedLocales } from '@/i18n/messages'
 import en from '@/i18n/locales/en'
 import zh from '@/i18n/locales/zh'
-import zhTW from '@/i18n/locales/zh-TW'
-import ja from '@/i18n/locales/ja'
-import ko from '@/i18n/locales/ko'
-import fr from '@/i18n/locales/fr'
-import es from '@/i18n/locales/es'
-import de from '@/i18n/locales/de'
-import pt from '@/i18n/locales/pt'
-import ru from '@/i18n/locales/ru'
 import { createI18n } from 'vue-i18n'
 
 const SOURCE_ROOT = join(process.cwd(), 'packages/client/src')
@@ -23,14 +15,6 @@ const allMessages: Record<string, Record<string, unknown>> = { en }
 const rawMessages: Record<string, Record<string, unknown>> = {
   en,
   zh,
-  'zh-TW': zhTW,
-  ja,
-  ko,
-  fr,
-  es,
-  de,
-  pt,
-  ru,
 }
 
 function walkFiles(dir: string, files: string[] = []): string[] {