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.

packages/server/src/index.ts

@@ -240,7 +240,7 @@ function startLanDiscovery(): void {
 }
 
 export async function bootstrap() {
-  console.log(`hermes-web-ui v${APP_VERSION} starting...`)
+  console.log(`hermes-ui v${APP_VERSION} starting...`)
   await mkdir(config.uploadDir, { recursive: true })
   if (shouldCreateWebUiDataDir()) {
     await mkdir(config.dataDir, { recursive: true })