feat: implement single-step migration with proper foreign key order

- Add migrateAll() function that handles complete migration in correct order:
  Accounts → Settings → Contacts to avoid foreign key constraint issues
- Add prominent "Migrate All (Recommended)" button to migration UI
- Add informational section explaining migration order and rationale
- Add info icon to icon set for UI clarity
- Improve migration logic to handle overwriteExisting parameter properly:
  - New records are always migrated regardless of checkbox setting
  - Existing records are only updated when overwriteExisting=true
  - Clear warning messages when records are skipped
- Maintain backward compatibility with individual migration buttons
- All code linted and formatted according to project standards

Co-authored-by: Matthew Raymer

src/assets/icons.json

@@ -66,5 +66,10 @@
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     "strokeWidth": "2",
     "d": "M12 6v6m0 0v6m0-6h6m-6 0H6"
+  },
+  "info": {
+    "fillRule": "evenodd",
+    "d": "M18 10a8 8 0 11-16 0 8 8 0 0116 0zm-7-4a1 1 0 11-2 0 1 1 0 012 0zM9 9a1 1 0 000 2v3a1 1 0 001 1h1a1 1 0 100-2v-3a1 1 0 00-1-1H9z",
+    "clipRule": "evenodd"
   }
 }