fix: prefix all client-side fetch calls with /ims basePath

Client components were calling fetch('/api/...') without the /ims prefix,
causing 404s in production where Next.js serves under basePath: '/ims'.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01FFDuBhMKvoWjrWT3ZnGmmr

components/settings/api-key-form.tsx

@@ -25,7 +25,7 @@ export function ApiKeyForm({ settings }: Props) {
     setSaving(s => ({ ...s, [key]: true }))
     setResults(r => ({ ...r, [key]: undefined as never }))
     try {
-      const res = await fetch('/api/settings', {
+      const res = await fetch('/ims/api/settings', {
         method: 'POST',
         headers: { 'Content-Type': 'application/json' },
         body: JSON.stringify({ key, value: values[key] }),