fix: presentation expiresAt — skip empty date, convert YYYY-MM-DD to end-of-day UTC

Empty string sent to Appwrite datetime column was being interpreted as creation
timestamp, making every no-expiry sunum immediately expired. Fix:
- Only include expiresAt in payload when user actually set a date
- Convert date-only string (YYYY-MM-DD) to YYYY-MM-DDT23:59:59.000Z so the
  sunum stays valid for the entire chosen day across all time zones
- Strip empty customerId/notes to avoid empty-string writes

src/lib/appwrite/presentation-actions.ts

@@ -30,6 +30,8 @@ export async function createPresentationAction(
   const data = parsed.data;
   const id = ID.unique();
   const shareToken = crypto.randomBytes(16).toString("hex");
+  // Convert "YYYY-MM-DD" → end-of-day UTC so the sunum is valid the full chosen day.
+  const expiresAt = data.expiresAt ? `${data.expiresAt}T23:59:59.000Z` : undefined;
 
   try {
     await tablesDB.createRow(
@@ -39,12 +41,12 @@ export async function createPresentationAction(
       {
         tenantId: ctx.tenantId,
         title: data.title,
-        customerId: data.customerId,
+        customerId: data.customerId || undefined,
         propertyIds: data.propertyIds,
         shareToken,
-        expiresAt: data.expiresAt,
+        ...(expiresAt ? { expiresAt } : {}),
         viewCount: 0,
-        notes: data.notes,
+        notes: data.notes || undefined,
         createdBy: ctx.user.id,
       },
       [
@@ -81,13 +83,15 @@ export async function updatePresentationAction(
   const { tablesDB } = createAdminClient();
   const data = parsed.data;
 
+  const expiresAt = data.expiresAt ? `${data.expiresAt}T23:59:59.000Z` : undefined;
+
   try {
     await tablesDB.updateRow(DATABASE_ID, TABLES.presentations, id, {
       title: data.title,
-      customerId: data.customerId,
+      customerId: data.customerId || undefined,
       propertyIds: data.propertyIds,
-      expiresAt: data.expiresAt,
-      notes: data.notes,
+      ...(expiresAt ? { expiresAt } : {}),
+      notes: data.notes || undefined,
     });
   } catch {
     return { ok: false, error: "Sunum güncellenemedi." };