fix(h2): refine SQL condition check for custom database flag (#4216)

# Description of Changes

- Refactored `H2SQLCondition.matches` to use `env.getProperty` with
proper default values and types.
- Adjusted logic to only return `false` when a custom database is
enabled and datasource type is not `h2`.
- Simplified environment variable handling for better readability and
robustness.

---

## Checklist

### General

- [x] I have read the [Contribution
Guidelines](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/CONTRIBUTING.md)
- [x] I have read the [Stirling-PDF Developer
Guide](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/DeveloperGuide.md)
(if applicable)
- [ ] I have read the [How to add new languages to
Stirling-PDF](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/HowToAddNewLanguage.md)
(if applicable)
- [x] I have performed a self-review of my own code
- [x] My changes generate no new warnings

### Documentation

- [ ] I have updated relevant docs on [Stirling-PDF's doc
repo](https://github.com/Stirling-Tools/Stirling-Tools.github.io/blob/main/docs/)
(if functionality has heavily changed)
- [ ] I have read the section [Add New Translation
Tags](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/HowToAddNewLanguage.md#add-new-translation-tags)
(for new translation tags only)

### UI Changes (if applicable)

- [ ] Screenshots or videos demonstrating the UI changes are attached
(e.g., as comments or direct attachments in the PR)

### Testing (if applicable)

- [ ] I have tested my changes locally. Refer to the [Testing
Guide](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/DeveloperGuide.md#6-testing)
for more details.

app/proprietary/src/main/java/stirling/software/proprietary/security/database/H2SQLCondition.java

@@ -8,16 +8,15 @@ public class H2SQLCondition implements Condition {
 
     @Override
     public boolean matches(ConditionContext context, AnnotatedTypeMetadata metadata) {
+        var env = context.getEnvironment();
         boolean enableCustomDatabase =
-                Boolean.parseBoolean(
+                env.getProperty("system.datasource.enableCustomDatabase", Boolean.class, false);
-                        context.getEnvironment()
-                                .getProperty("system.datasource.enableCustomDatabase"));
 
-        if (!enableCustomDatabase) {
+        if (enableCustomDatabase) {
             return false;
         }
 
-        String dataSourceType = context.getEnvironment().getProperty("system.datasource.type");
+        String dataSourceType = env.getProperty("system.datasource.type", String.class, "");
         return "h2".equalsIgnoreCase(dataSourceType);
     }
 }