add composer-unused, comprehensive docs, and project restructure

- Add icanhazstring/composer-unused as dev dependency for dependency hygiene checks
- Add German documentation (docs/) covering architecture, conventions, workflows, and developer checklists
- Add API layer (ApiAuth, ApiBootstrap, ApiResponse), audit, scheduler, custom fields, and SSO services
- Add Microsoft OIDC SSO, API token management, and user lifecycle features
- Add swagger-ui vendor integration and OpenAPI spec
- Add production Docker setup and bin/ scripts
- Update composer dependencies, config, templates, and frontend assets throughout

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

lib/Service/Import/Profile/ImportProfileInterface.php

@@ -0,0 +1,63 @@
+<?php
+
+namespace MintyPHP\Service\Import\Profile;
+
+interface ImportProfileInterface
+{
+    public function key(): string;
+
+    public function label(): string;
+
+    /**
+     * @return array<string, string> target => label
+     */
+    public function allowedTargets(): array;
+
+    /**
+     * @return array<int, string>
+     */
+    public function requiredTargets(): array;
+
+    /**
+     * @return array<string, array<int, string>> target => aliases
+     */
+    public function autoMapAliases(): array;
+
+    public function supportsAssignments(): bool;
+
+    public function requiresAssignmentPermission(): bool;
+
+    /**
+     * @param array<string, string> $mapped
+     * @param array<string, mixed> $context
+     * @return array{ok:bool, normalized:array<string,mixed>, errors:array<int,array{code:string,message?:string}>}
+     */
+    public function validateMappedRow(array $mapped, array $context): array;
+
+    /**
+     * @param array<string, mixed> $normalized
+     * @param array<string, mixed> $context
+     * @return array{status:string, code?:string, message?:string}
+     */
+    public function dryRunRow(array $normalized, array $context): array;
+
+    /**
+     * @param array<string, mixed> $normalized
+     * @param array<string, mixed> $context
+     * @return array{status:string, code?:string, message?:string, uuid?:string}
+     */
+    public function commitRow(array $normalized, array $context): array;
+
+    /**
+     * Returns a deterministic key for in-file duplicate detection.
+     * Return null when duplicate detection is not required for this row.
+     *
+     * @param array<string, mixed> $normalized
+     */
+    public function inFileDuplicateKey(array $normalized): ?string;
+
+    /**
+     * @param array<string, mixed> $normalized
+     */
+    public function rowIdentifier(array $normalized): string;
+}