Rebrand: Co-op Check-in -> Co-op Survey in user-facing copy

Updates the tool product name across the app UI (header, page title,
section labels, form buttons, success/error states, report stat labels),
README, deployment docs, and the CiviCRM email template guidance.
Custom domain references move from check-in.fci.coop to survey.fci.coop
(DNS update still required).

The underlying CiviCRM "Check-in (organizing)" activity type, custom
group machine names (Check_in_data__organizing_), health-check ids,
and the internal org_engagement_check_in form id are unchanged --
those are CiviCRM contract surfaces, not product copy.

components/EngagementForm.tsx

@@ -429,7 +429,7 @@ function SubmissionContextHeader({
 }) {
   return (
     <header className="rounded-lg border border-rule bg-paper-2/40 px-6 py-5 sm:px-7 sm:py-6">
-      <p className="text-[11px] uppercase tracking-[0.18em] text-ink-mute">Check-in for</p>
+      <p className="text-[11px] uppercase tracking-[0.18em] text-ink-mute">Survey for</p>
       <h1 className="mt-1 font-display text-3xl font-medium leading-tight tracking-tight text-ink sm:text-[34px]">
         {orgName}
       </h1>
@@ -551,7 +551,7 @@ function SubmitBar({
   } else if (state.kind === "submitting") {
     secondary = (
       <p className="truncate text-xs text-ink-soft" role="status">
-        Saving your check-in…
+        Saving your survey…
       </p>
     );
   } else if (viewedSectionLabel && viewedRank != null) {
@@ -604,10 +604,10 @@ function SubmitBar({
       >
         {state.kind === "submitting" ? (
           <>
-            <Spinner /> Saving check-in…
+            <Spinner /> Saving survey…
           </>
         ) : (
-          <>Submit check-in</>
+          <>Submit survey</>
         )}
       </button>
     </div>
@@ -636,7 +636,7 @@ function LoadingState() {
         aria-hidden
         className="mx-auto mb-4 h-7 w-7 animate-spin rounded-full border-[1.5px] border-rule border-t-leaf-700"
       />
-      <p className="font-display text-base text-ink-soft italic">Loading your check-in…</p>
+      <p className="font-display text-base text-ink-soft italic">Loading your survey…</p>
     </div>
   );
 }
@@ -663,10 +663,10 @@ function SuccessDestination({
         </svg>
       </div>
       <h2 className="mt-5 font-display text-2xl font-medium leading-tight tracking-tight text-ink sm:text-3xl">
-        Check-in saved
+        Survey saved
       </h2>
       <p className="mx-auto mt-3 max-w-prose text-[15px] leading-relaxed text-ink-soft">
-        Thank you. We&apos;ve recorded this check-in for{" "}
+        Thank you. We&apos;ve recorded this survey for{" "}
         <span className="font-medium text-ink">{orgName}</span>. Your engagement coordinator will see
         it on their next review.
       </p>
@@ -676,7 +676,7 @@ function SuccessDestination({
           onClick={onAnother}
           className="inline-flex items-center justify-center rounded-md border border-rule bg-paper px-5 py-2 text-sm font-medium text-ink-soft transition hover:bg-paper-2/60 focus:outline-none focus-visible:ring-2 focus-visible:ring-leaf-500/40"
         >
-          Submit another check-in
+          Submit another survey
         </button>
         <p className="text-xs text-ink-mute">It&apos;s safe to close this window.</p>
       </div>
@@ -691,7 +691,7 @@ function ErrorState({ message }: { message: string }) {
       className="rounded-lg border-2 border-clay-200 bg-clay-100/30 px-6 py-7"
     >
       <h2 className="font-display text-xl font-medium text-clay-700">
-        We couldn&apos;t open your check-in.
+        We couldn&apos;t open your survey.
       </h2>
       <p className="mt-3 text-sm leading-relaxed text-ink-soft">{message}</p>
       <p className="mt-4 text-sm text-ink-soft">