Reapply "Add missing admin action files and navigation links"

This reverts commit 4d515bc400.

src/app/admin/translations/client/page.tsx

@@ -0,0 +1,51 @@
+import fs from 'node:fs/promises'
+import path from 'node:path'
+import JSON5 from 'json5'
+import { CLIENT_TRANSLATION_FILES, getClientTranslationFile } from '@/lib/client-translation-files'
+import { ClientTranslations } from './client-translations'
+
+export default async function ClientTranslationsPage({
+  searchParams,
+}: {
+  searchParams: Promise<Record<string, string | undefined>>
+}) {
+  const sp = await searchParams
+  const requested = sp.file
+  const file =
+    (requested && getClientTranslationFile(requested)) ||
+    CLIENT_TRANSLATION_FILES.find((f) => !f.readOnly) ||
+    CLIENT_TRANSLATION_FILES[0]
+
+  const entries: Record<string, string> = {}
+  let parseError: string | null = null
+
+  try {
+    // file.relPath comes from CLIENT_TRANSLATION_FILES (closed enum) but
+    // Turbopack's tracer can't prove that — hint avoids tracing the whole project.
+    const raw = await fs.readFile(
+      path.join(/*turbopackIgnore: true*/ process.cwd(), file.relPath),
+      'utf-8',
+    )
+    const parsed = file.format === 'json5' ? JSON5.parse(raw) : JSON.parse(raw)
+    if (parsed && typeof parsed === 'object' && !Array.isArray(parsed)) {
+      // Nitro localization files are flat: { "key.with.dots": "value" }.
+      // Coerce values to strings so the editor can render them in <input>.
+      for (const [k, v] of Object.entries(parsed)) {
+        entries[k] = v == null ? '' : String(v)
+      }
+    } else {
+      parseError = 'File root is not an object.'
+    }
+  } catch (err) {
+    parseError = err instanceof Error ? err.message : 'Failed to read file.'
+  }
+
+  return (
+    <ClientTranslations
+      files={CLIENT_TRANSLATION_FILES}
+      activeFile={file}
+      entries={entries}
+      parseError={parseError}
+    />
+  )
+}