feat: enforce exhaustive unit testing and 100% SonarQube branch coverage

- Enforce mandatory handle() and failed() method testing for all Jobs and Commands
- Ban shallow reflection-only helper testing in Jobs
- Mandate actual SQLite in-memory query execution for Repositories (ban Builder::class assertions alone)
- Enforce full branch coverage for SonarQube (ternary, null-coalescing, catch blocks, match)
- Update JobTest templates for PHPUnit and Pest to include handle() and failed() methods
- Update verification checklist and master system prompt with strict branch gatekeepers

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

templates/phpunit/JobTest.template.php

@@ -32,4 +32,18 @@ class {{ClassName}}Test extends TestCase
         // Assert
         $this->assertTrue(true);
     }
+
+    #[Test]
+    public function it_handles_job_failure_cleanly(): void
+    {
+        // Arrange
+        // $job = new {{ClassName}}(...);
+        // $exception = new \RuntimeException('Job failed');
+
+        // Act
+        // $job->failed($exception);
+
+        // Assert
+        $this->assertTrue(true);
+    }
 }