Quality: Add Unit Tests for apis-web Controllers

[thechibuikem]

Added comprehensive unit test coverage for three critical API handlers in apis-web, directly addressing issue #93's requirement to improve test coverage.

Tests Added:

• DealGenerationTest (7 tests) - validates deal creation endpoint, JSON parsing, EventBus messaging
• LogConfigurationTest (7 tests) - validates log level configuration, multicast handler support
• ErrorGenerationTest (6 tests) - validates error generation endpoint, form field handling

Test Coverage:
Each test class covers:

• Path matching validation (accepts correct paths, rejects others)
• HTTP method handling (GET returns HTML form, POST processes data, others return 405)
• Happy path scenarios (valid data successfully processed)
• Error scenarios (invalid data, malformed JSON, exceptions return 500)
• Mocked external dependencies (EventBus, HTTP request/response, Logger)

Dependencies Required:

<dependency>
    <groupId>org.junit.jupiter</groupId>
    <artifactId>junit-jupiter-api</artifactId>
    <version>5.9.3</version>
    <scope>test</scope>
</dependency>
<dependency>
    <groupId>org.junit.jupiter</groupId>
    <artifactId>junit-jupiter-engine</artifactId>
    <version>5.9.3</version>
    <scope>test</scope>
</dependency>
<dependency>
    <groupId>org.mockito</groupId>
    <artifactId>mockito-core</artifactId>
    <version>5.2.0</version>
    <scope>test</scope>
</dependency>

Issues & Notes:

• BOM declares Vertx 5.0.7 but codebase uses 4.x APIs
• Tests use JUnit 5 (project currently uses JUnit 4)
• Uses ArgumentCaptor to test callback handlers (POST endHandler pattern)

Next: apis-main tests coming in separate PR.