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

src/Application/Admin/ValueObjects/NavigationItem.php

@@ -0,0 +1,51 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Application\Admin\ValueObjects;
+
+final readonly class NavigationItem
+{
+    public function __construct(
+        public string $name,
+        public string $url,
+        public ?string $icon = null,
+        public bool $isActive = false
+    ) {
+    }
+
+    public static function fromArray(array $data): self
+    {
+        return new self(
+            name: $data['name'] ?? '',
+            url: $data['url'] ?? '',
+            icon: $data['icon'] ?? null,
+            isActive: $data['is_active'] ?? false
+        );
+    }
+
+    public function toArray(): array
+    {
+        return [
+            'name' => $this->name,
+            'url' => $this->url,
+            'icon' => $this->icon,
+            'is_active' => $this->isActive,
+        ];
+    }
+
+    public function withActiveState(bool $isActive): self
+    {
+        return new self(
+            name: $this->name,
+            url: $this->url,
+            icon: $this->icon,
+            isActive: $isActive
+        );
+    }
+
+    public function isActive(string $currentPath): bool
+    {
+        return $this->url === $currentPath || str_starts_with($currentPath, $this->url);
+    }
+}