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/Domain/Media/ImagickImageProcessor.php

@@ -59,7 +59,7 @@ final readonly class ImagickImageProcessor implements ImageProcessorInterface
      */
     private function createVariant(Image $image, array $config): ImageVariant
     {
-        $sourcePath = $image->path . $image->filename;
+        $sourcePath = $image->path->join($image->filename)->toString();
 
         /** @var ImageVariantType $type */
         /** @var ImageSize $size */
@@ -76,14 +76,14 @@ final readonly class ImagickImageProcessor implements ImageProcessorInterface
             $format->value
         );
 
-        $destination = $image->path . $filename;
+        $destination = $image->path->join($filename)->toString();
 
         $actualDimensions = $this->processImage($sourcePath, $destination, $width, $format);
 
         $fileSize = filesize($destination);
 
         return new ImageVariant(
-            imageId: $image->ulid,
+            imageId: (string) $image->ulid,
             variantType: $type->value,
             size: $size->value,
             format: $format->value,
@@ -92,7 +92,7 @@ final readonly class ImagickImageProcessor implements ImageProcessorInterface
             width: $actualDimensions['width'],
             height: $actualDimensions['height'],
             filename: $filename,
-            path: $image->path,
+            path: $image->path->toString(),
         );
     }