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/capa/capa-form.tsx

@@ -39,7 +39,7 @@ export function CapaForm({ incidentId, users }: Props) {
     }
     setSaving(true)
     setError(null)
-    const res = await fetch('/api/capa', {
+    const res = await fetch('/ims/api/capa', {
       method: 'POST',
       headers: { 'Content-Type': 'application/json' },
       body: JSON.stringify({