fix: snapshot deletion, restore grid logic and add diagnostic API

src/features/snapshots/api/delete-snapshot.ts

@@ -7,18 +7,31 @@ import { auth } from "@/lib/auth";
 
 export async function deleteSnapshot(id: number) {
     const session = await auth();
-    const userId = session?.user ? Number((session.user as any).id) : null;
+    const rawUserId = (session?.user as any)?.id;
+    const userId = rawUserId ? parseInt(String(rawUserId), 10) : null;
 
-    if (!userId) {
+    console.log(`[deleteSnapshot] Request for ID: ${id}, Session UserId: ${userId} (raw: ${rawUserId})`);
+
+    if (!userId || isNaN(userId)) {
+        console.error("[deleteSnapshot] Unauthorized: userId is missing or invalid");
         return { success: false, error: "Non autorisé" };
     }
 
     try {
-        await db.delete(sessionSnapshots)
-            .where(and(eq(sessionSnapshots.id, id), eq(sessionSnapshots.userId, userId)));
+        const result = await db.delete(sessionSnapshots)
+            .where(and(eq(sessionSnapshots.id, id), eq(sessionSnapshots.userId, userId)))
+            .returning({ deletedId: sessionSnapshots.id });
+        
+        if (result.length === 0) {
+            console.warn(`[deleteSnapshot] No rows deleted for ID ${id} and User ${userId}. Maybe the snapshot doesn't belong to the user?`);
+            // We return success: false to trigger the error modal in UI if nothing was actually deleted
+            return { success: false, error: "Élément non trouvé ou non autorisé" };
+        }
+
+        console.log(`[deleteSnapshot] Successfully deleted ID: ${id}`);
         return { success: true };
-    } catch (err) {
-        console.error(err);
-        return { success: false, error: "Delete failed" };
+    } catch (err: any) {
+        console.error("[deleteSnapshot] DB Error:", err);
+        return { success: false, error: err.message || "Delete failed" };
     }
 }