start adding the SQL approach to files, also using the Dexie approach if desired

doc/secure-storage-implementation.md

@@ -209,12 +209,8 @@ When converting from Dexie.js to SQL-based implementation, follow these patterns
    ```
 
 Key Considerations:
-1. Always use parameterized queries to prevent SQL injection
-2. Use the `generateUpdateStatement` helper for update operations
-3. Use the `mapColumnsToValues` helper for processing query results
-4. Handle transactions explicitly for batch operations
-5. Use appropriate error handling with the StorageError class
-6. Consider platform-specific capabilities when implementing features
+- Use the `generateUpdateStatement` helper for update operations
+- Use the `mapColumnsToValues` helper for processing query results
 
 Example Migration:
 ```typescript
@@ -238,7 +234,12 @@ export async function updateSettings(settings: Settings): Promise<void> {
 
 Remember to:
 - Create database access code to use the platform service, putting it in front of the Dexie version
-- Instead of removing Dexie-specific code, keep it; if we use the results of the query, then check the USE_DEXIE_DB from app.ts and if it's true then use that instead of the SQL code. 
+- Instead of removing Dexie-specific code, keep it.
+
+  - For creates & updates & deletes, the duplicate code is fine.
+  
+  - For queries where we use the results, make the setting from SQL into a 'let' variable, then wrap the Dexie code in a check for USE_DEXIE_DB from app.ts and if it's true then use that result instead of the SQL code's result. 
+
 - Test thoroughly after migration
 - Consider data migration needs, and warn if there are any potential migration problems