docs: consolidate documentation into organized structure

- Move 12 markdown files from root to docs/ subdirectories
- Organize documentation by category:
  • docs/troubleshooting/ (1 file)  - Technical troubleshooting guides
  • docs/deployment/      (4 files) - Deployment and security documentation
  • docs/guides/          (3 files) - Feature-specific guides
  • docs/planning/        (4 files) - Planning and improvement proposals

Root directory cleanup:
- Reduced from 16 to 4 markdown files in root
- Only essential project files remain:
  • CLAUDE.md (AI instructions)
  • README.md (Main project readme)
  • CLEANUP_PLAN.md (Current cleanup plan)
  • SRC_STRUCTURE_IMPROVEMENTS.md (Structure improvements)

This improves:
✅ Documentation discoverability
✅ Logical organization by purpose
✅ Clean root directory
✅ Better maintainability

tests/Framework/MagicLinks/ValueObjects/MetadataTest.php

@@ -0,0 +1,51 @@
+<?php
+
+use App\Framework\MagicLinks\ValueObjects\Metadata;
+
+describe('Metadata', function () {
+    it('creates empty metadata', function () {
+        $metadata = Metadata::empty();
+
+        expect($metadata->isEmpty())->toBeTrue();
+        expect($metadata->toArray())->toBe([]);
+    });
+
+    it('creates from array', function () {
+        $metadata = Metadata::fromArray(['source' => 'email', 'campaign' => 'welcome']);
+
+        expect($metadata->isEmpty())->toBeFalse();
+        expect($metadata->toArray())->toBe(['source' => 'email', 'campaign' => 'welcome']);
+    });
+
+    it('adds values immutably', function () {
+        $metadata = Metadata::empty();
+        $updated = $metadata->with('source', 'email');
+
+        expect($metadata->has('source'))->toBeFalse();
+        expect($updated->has('source'))->toBeTrue();
+        expect($updated->get('source'))->toBe('email');
+    });
+
+    it('removes values immutably', function () {
+        $metadata = Metadata::fromArray(['source' => 'email', 'campaign' => 'welcome']);
+        $updated = $metadata->without('campaign');
+
+        expect($metadata->has('campaign'))->toBeTrue();
+        expect($updated->has('campaign'))->toBeFalse();
+        expect($updated->has('source'))->toBeTrue();
+    });
+
+    it('merges metadata', function () {
+        $meta1 = Metadata::fromArray(['source' => 'email']);
+        $meta2 = Metadata::fromArray(['campaign' => 'welcome']);
+        $merged = $meta1->merge($meta2);
+
+        expect($merged->toArray())->toBe(['source' => 'email', 'campaign' => 'welcome']);
+    });
+
+    it('returns keys', function () {
+        $metadata = Metadata::fromArray(['source' => 'email', 'campaign' => 'welcome']);
+
+        expect($metadata->keys())->toBe(['source', 'campaign']);
+    });
+});