convert to dao calls, prep for migration strategy and first start db seed

lib/screens/sessions_screen.dart

@@ -1,19 +1,18 @@
 import 'package:flutter/material.dart';
+import 'package:provider/provider.dart';
 import 'package:sendtrain/database/daos/sessions_dao.dart';
 import 'package:sendtrain/database/database.dart';
 import '../widgets/session_card.dart';
 
 class SessionsScreen extends StatelessWidget {
-  final AppDatabase database = AppDatabase();
-  SessionsScreen({super.key});
+  const SessionsScreen({super.key});
 
   @override
   Widget build(BuildContext context) {
     return FutureBuilder<List<Session>>(
-        future: SessionsDao(database).all(),
+        future: SessionsDao(Provider.of<AppDatabase>(context)).all(),
         builder: (context, snapshot) {
           if (snapshot.hasData) {
-            database.close();
             final sessions = snapshot.data!;
             final pending = sessions.where((session) =>
                 session.status == SessionStatus.completed ||
@@ -28,8 +27,6 @@ class SessionsScreen extends StatelessWidget {
             Widget upcomingSession = SessionCard(session: upcoming);
             Widget currentSession = SessionCard(session: current);
 
-            database.close();
-
             return Column(
               crossAxisAlignment: CrossAxisAlignment.start,
               children: <Widget>[
@@ -66,7 +63,13 @@ class SessionsScreen extends StatelessWidget {
               ],
             );
           } else {
-            return const CircularProgressIndicator();
+            return Container(
+                alignment: Alignment.center,
+                child: SizedBox(
+                  height: 50.0,
+                  width: 50.0,
+                  child: CircularProgressIndicator(),
+                ));
           }
         });
   }