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/server/profiles-routes.test.ts

@@ -315,7 +315,7 @@ describe('Profile Routes', () => {
 
   describe('profile avatars', () => {
     it('stores generated avatar metadata under the Web UI home', async () => {
-      const webUiHome = await mkdtemp(join(tmpdir(), 'hermes-web-ui-avatar-'))
+      const webUiHome = await mkdtemp(join(tmpdir(), 'hermes-ui-avatar-'))
       tempHomes.push(webUiHome)
       process.env.HERMES_WEB_UI_HOME = webUiHome
       const { updateAvatar } = await import('../../packages/server/src/controllers/hermes/profiles')
@@ -338,7 +338,7 @@ describe('Profile Routes', () => {
     })
 
     it('stores uploaded image avatars and returns a data URL', async () => {
-      const webUiHome = await mkdtemp(join(tmpdir(), 'hermes-web-ui-avatar-'))
+      const webUiHome = await mkdtemp(join(tmpdir(), 'hermes-ui-avatar-'))
       tempHomes.push(webUiHome)
       process.env.HERMES_WEB_UI_HOME = webUiHome
       const dataUrl = `data:image/png;base64,${Buffer.from('avatar-png').toString('base64')}`
@@ -361,7 +361,7 @@ describe('Profile Routes', () => {
     })
 
     it('deletes profile avatar metadata', async () => {
-      const webUiHome = await mkdtemp(join(tmpdir(), 'hermes-web-ui-avatar-'))
+      const webUiHome = await mkdtemp(join(tmpdir(), 'hermes-ui-avatar-'))
       tempHomes.push(webUiHome)
       process.env.HERMES_WEB_UI_HOME = webUiHome
       const metadataDir = join(webUiHome, 'profile-metadata', Buffer.from('work', 'utf-8').toString('base64url'))