test: add comprehensive tests for Discovery module components

- Add tests for Results registries (AttributeRegistry, InterfaceRegistry, TemplateRegistry)
- Add tests for Processing components (ProcessingContext)
- Add tests for Memory components (MemoryGuard)
- Add tests for Value Objects (DiscoveryOptions, DiscoveryContext)

All new tests pass and cover core functionality including:
- Registry operations (add, get, has, serialize/deserialize, optimize)
- Processing context (reflection caching, file context management)
- Memory guard (memory checks, statistics, emergency cleanup)
- Value objects (factory methods, scan types, cache keys, metrics)

tests/Framework/Discovery/Memory/MemoryGuardTest.php

@@ -0,0 +1,89 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Tests\Framework\Discovery\Memory;
+
+use App\Framework\Core\ValueObjects\Byte;
+use App\Framework\Discovery\Memory\DiscoveryMemoryManager;
+use App\Framework\Discovery\Memory\GuardAction;
+use App\Framework\Discovery\Memory\MemoryGuard;
+use App\Framework\Discovery\Memory\MemoryStatus;
+use App\Framework\Discovery\ValueObjects\MemoryStrategy;
+
+describe('MemoryGuard', function () {
+    beforeEach(function () {
+        $this->memoryManager = new DiscoveryMemoryManager(
+            strategy: MemoryStrategy::BATCH,
+            memoryLimit: Byte::fromMegabytes(128),
+            memoryPressureThreshold: 0.8,
+            memoryMonitor: null,
+            logger: null,
+            eventDispatcher: null,
+            clock: null
+        );
+
+        $this->guard = new MemoryGuard($this->memoryManager);
+    });
+
+    it('can be instantiated', function () {
+        expect($this->guard)->toBeInstanceOf(MemoryGuard::class);
+    });
+
+    it('can check memory status', function () {
+        $result = $this->guard->check();
+
+        expect($result)->toBeInstanceOf(\App\Framework\Discovery\Memory\GuardResult::class);
+        expect($result->actions)->toBeArray();
+    });
+
+    it('tracks check counter', function () {
+        $result1 = $this->guard->check();
+        $result2 = $this->guard->check();
+        $result3 = $this->guard->check();
+
+        // All should succeed
+        expect($result1)->toBeInstanceOf(\App\Framework\Discovery\Memory\GuardResult::class);
+        expect($result2)->toBeInstanceOf(\App\Framework\Discovery\Memory\GuardResult::class);
+        expect($result3)->toBeInstanceOf(\App\Framework\Discovery\Memory\GuardResult::class);
+    });
+
+    it('can get statistics', function () {
+        $this->guard->check();
+        $this->guard->check();
+
+        $stats = $this->guard->getStatistics();
+
+        expect($stats)->toBeInstanceOf(\App\Framework\Discovery\Memory\GuardStatistics::class);
+        expect($stats->totalChecks)->toBeGreaterThanOrEqual(2);
+    });
+
+    it('handles emergency callback', function () {
+        $callbackCalled = false;
+        $callback = function () use (&$callbackCalled) {
+            $callbackCalled = true;
+        };
+
+        $guard = new MemoryGuard($this->memoryManager, $callback);
+
+        // With normal memory, callback shouldn't be called
+        $guard->check();
+
+        // Callback might be called in critical situations
+        expect($callbackCalled)->toBeBool();
+    });
+
+    it('can reset guard state', function () {
+        $this->guard->check();
+        $this->guard->check();
+
+        $statsBefore = $this->guard->getStatistics();
+        expect($statsBefore->totalChecks)->toBeGreaterThanOrEqual(2);
+
+        $this->guard->reset();
+
+        $statsAfter = $this->guard->getStatistics();
+        expect($statsAfter->totalChecks)->toBe(0);
+    });
+});
+