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/Framework/Logging/Commands/RotateLogsCommand.php

@@ -14,7 +14,7 @@ use App\Framework\Logging\LogRotator;
 final readonly class RotateLogsCommand
 {
     #[ConsoleCommand(name: "logs:rotate", description: "Rotiert Log-Dateien basierend auf Größe und Anzahl")]
-    public function execute(ConsoleInput $input, ConsoleOutput $output): int
+    public function execute(ConsoleInput $input, ConsoleOutput $output): ExitCode
     {
         $output->writeLine('<info>Starting log rotation...</info>');
 
@@ -61,7 +61,7 @@ final readonly class RotateLogsCommand
         $output->writeLine("  Files rotated: {$rotatedCount}");
         $output->writeLine("  Total log size: " . $totalSize->toHumanReadable());
 
-        return ExitCode::SUCCESS->value;
+        return ExitCode::SUCCESS;
     }
 
     private function getLogPaths(): array