Add prompt to continue from most recent saved run

When tapping Start with existing saved runs, shows dialog asking
whether to continue from last run or start fresh. Continuing pre-fills
all profile and behavior inputs from the saved run.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

lib/screens/baseline_screen.dart

@@ -9,11 +9,13 @@ import 'behavioral_screen.dart';
 class BaselineScreen extends StatefulWidget {
   final bool readOnly;
   final UserProfile? initialProfile;
+  final BehavioralInputs? initialBehaviors;
 
   const BaselineScreen({
     super.key,
     this.readOnly = false,
     this.initialProfile,
+    this.initialBehaviors,
   });
 
   @override
@@ -479,7 +481,10 @@ class _BaselineScreenState extends State<BaselineScreen> {
     if (mounted) {
       Navigator.of(context).push(
         MaterialPageRoute(
-          builder: (_) => BehavioralScreen(profile: profile),
+          builder: (_) => BehavioralScreen(
+            profile: profile,
+            initialBehaviors: widget.initialBehaviors,
+          ),
         ),
       );
     }

lib/screens/welcome_screen.dart

@@ -1,4 +1,5 @@
 import 'package:flutter/material.dart';
+import '../models/models.dart';
 import '../storage/local_storage.dart';
 import '../theme.dart';
 import 'about_screen.dart';
@@ -57,7 +58,7 @@ class WelcomeScreen extends StatelessWidget {
               SizedBox(
                 width: double.infinity,
                 child: ElevatedButton(
-                  onPressed: () => _navigateToBaseline(context),
+                  onPressed: () => _handleStart(context),
                   child: const Text('Start'),
                 ),
               ),
@@ -88,9 +89,70 @@ class WelcomeScreen extends StatelessWidget {
     );
   }
 
-  void _navigateToBaseline(BuildContext context) {
+  Future<void> _handleStart(BuildContext context) async {
+    final recentRun = await LocalStorage.getMostRecentSavedRun();
+
+    if (recentRun == null) {
+      // No saved runs, start fresh
+      if (context.mounted) {
+        _navigateToBaseline(context, null, null);
+      }
+      return;
+    }
+
+    // Show dialog to choose between continuing or starting fresh
+    if (context.mounted) {
+      _showContinueDialog(context, recentRun);
+    }
+  }
+
+  void _showContinueDialog(BuildContext context, SavedRun recentRun) {
+    showDialog(
+      context: context,
+      builder: (dialogContext) => AlertDialog(
+        title: const Text('Continue from last run?'),
+        content: Text(
+          'You have a saved run from ${recentRun.displayDate}. '
+          'Would you like to start with those inputs and make adjustments?',
+        ),
+        actions: [
+          TextButton(
+            onPressed: () {
+              Navigator.pop(dialogContext);
+              _navigateToBaseline(context, null, null);
+            },
+            child: const Text('Start Fresh'),
+          ),
+          TextButton(
+            onPressed: () {
+              Navigator.pop(dialogContext);
+              _navigateToBaseline(
+                context,
+                recentRun.profile,
+                recentRun.behaviors,
+              );
+            },
+            child: const Text('Continue'),
+          ),
+        ],
+      ),
+    );
+  }
+
+  void _navigateToBaseline(
+    BuildContext context,
+    UserProfile? profile,
+    BehavioralInputs? behaviors,
+  ) {
+    if (!context.mounted) return;
+
     Navigator.of(context).push(
-      MaterialPageRoute(builder: (_) => const BaselineScreen()),
+      MaterialPageRoute(
+        builder: (_) => BaselineScreen(
+          initialProfile: profile,
+          initialBehaviors: behaviors,
+        ),
+      ),
     );
   }
 

lib/storage/local_storage.dart

@@ -257,6 +257,33 @@ class LocalStorage {
     return result.first['count'] as int;
   }
 
+  static Future<SavedRun?> getMostRecentSavedRun() async {
+    final db = await database;
+    final results = await db.query(
+      _savedRunsTable,
+      orderBy: 'created_at DESC',
+      limit: 1,
+    );
+
+    if (results.isEmpty) return null;
+
+    final row = results.first;
+    return SavedRun(
+      id: row['id'] as String,
+      label: row['label'] as String,
+      result: CalculationResult.fromJson(
+        jsonDecode(row['result'] as String) as Map<String, dynamic>,
+      ),
+      profile: UserProfile.fromJson(
+        jsonDecode(row['profile'] as String) as Map<String, dynamic>,
+      ),
+      behaviors: BehavioralInputs.fromJson(
+        jsonDecode(row['behaviors'] as String) as Map<String, dynamic>,
+      ),
+      createdAt: DateTime.fromMillisecondsSinceEpoch(row['created_at'] as int),
+    );
+  }
+
   // ============================================
   // Unit preference operations
   // ============================================