feat: setup wizard for new databases (discussion #523)

docs/ARCHITECTURE.md

@@ -237,7 +237,7 @@ submersion/
 │   │   ├── dive_types/              # Custom dive types
 │   │   ├── marine_life/             # Species sightings
 │   │   ├── tools/                   # Calculators
-│   │   └── onboarding/              # First-run experience
+│   │   └── setup_wizard/            # First-run setup wizard + Settings re-entry
 │   │
 │   └── shared/                      # Reusable components
 │       ├── constants/

docs/FEATURE_ROADMAP.md

@@ -1303,6 +1303,13 @@
 
 ---
 
+### Setup Wizard (Completed)
+
+- [x] Setup wizard for new databases (discussion #523): first-run fork
+      (fresh start vs existing data), units with locale-aware preset,
+      appearance, backup schedule and cloud sync connect, restore/adopt
+      paths, feature-discovery finish screen, Settings re-entry
+
 ## 15.2 Multi-User / Family Support
 
 | Feature | Status | Phase | Notes |

docs/developer/architecture.md

@@ -157,7 +157,7 @@ lib/
 │   ├── dive_types/
 │   ├── marine_life/
 │   ├── tools/
-│   └── onboarding/
+│   └── setup_wizard/
 │
 └── shared/                      # Shared components
     ├── constants/

docs/developer/navigation.md

@@ -330,7 +330,8 @@ GoRoute(
 
 | Path | Name | Screen |
 |------|------|--------|
-| `/welcome` | welcome | WelcomePage |
+| `/welcome` | welcome | SetupWizardPage (first-run mode) |
+| `/settings/setup-assistant` | setupAssistant | SetupWizardPage (re-entry mode) |
 
 ## Navigation Patterns
 
@@ -394,7 +395,10 @@ This provides instant transitions between main tabs, matching platform conventio
 
 ### First-Run Guard
 
-The router redirects to onboarding if no divers exist:
+The router redirects to the setup wizard if no divers exist. The wizard
+offers a fresh-start path (profile, units, appearance, backup and sync) and
+an existing-data path (restore a backup, connect cloud sync, or open an
+existing storage folder):
 
 ```dart
 redirect: (context, state) async {

docs/guide/README.md

@@ -30,7 +30,7 @@ Submersion has five main sections accessible from the bottom navigation bar (mob
 
 ### Core Workflow
 
-1. **Create a diver profile** - On first launch, you'll set up your diver profile
+1. **Run the setup wizard** - On first launch, create your profile and pick units, appearance, and backup options (or restore existing data)
 2. **Add dive sites** - Build your site database (or import existing sites)
 3. **Log dives** - Manually or download from a dive computer
 4. **Track gear** - Add your equipment with service reminders

docs/guide/first-dive.md

@@ -2,18 +2,23 @@
 
 Let's log your first dive in Submersion! This quick tutorial will get you familiar with the basics.
 
-## Step 1: Create Your Diver Profile
+## Step 1: Run the Setup Wizard
 
-When you first launch Submersion, you'll be asked to create a diver profile.
+When you first launch Submersion, a short setup wizard walks you through
+creating your logbook. If you already have Submersion data, choose
+**I have existing Submersion data** to restore a backup, connect cloud
+sync, or open an existing folder instead.
 
 <div class="screenshot-placeholder">
-  <strong>Screenshot: Welcome/Onboarding Screen</strong><br>
-  <em>The welcome screen where you create your first diver profile</em>
+  <strong>Screenshot: Setup Wizard Welcome Screen</strong><br>
+  <em>The welcome screen where setup begins</em>
 </div>
 
-1. Enter your **name**
-2. Optionally add your **email** and **phone**
-3. Tap **Create Profile**
+1. Choose **Set up a new logbook**
+2. Enter your **name**
+3. Pick your **units** (Metric or Imperial), appearance, and backup
+   preferences - every step after the name can be skipped
+4. Tap **Start logging**
 
 <div class="tip">
 <strong>Tip:</strong> You can add more details to your profile later, including emergency contacts, medical info, and insurance details.