Migrate omsorgapp to browser SPA, add Docker/CI build setup

- omsorgapp: drop Electron, run as a plain Vite/React browser app; refresh
  token moves to an HttpOnly cookie (omsorgCore), CORS added for the new
  browser origin, document download/preview switched to Blob-based browser
  APIs.
- Add Dockerfiles for omsorgCore, omsorgapp, and omsorgWeb, a docker-compose.yml
  wiring Postgres/MySQL/all three apps together, and a Gitea Actions workflow
  that builds and pushes images to the repo's container registry on push to
  main and on version tags.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

omsorgWeb/mitarbeiter-app/api-client-php/test/Model/PermissionActionTest.php

@@ -0,0 +1,81 @@
+<?php
+/**
+ * PermissionActionTest
+ *
+ * PHP version 8.1
+ *
+ * @category Class
+ * @package  OmsorgCoreClient
+ * @author   OpenAPI Generator team
+ * @link     https://openapi-generator.tech
+ */
+
+/**
+ * OmsorgCore.Api
+ *
+ * No description provided (generated by Openapi Generator https://github.com/openapitools/openapi-generator)
+ *
+ * The version of the OpenAPI document: 1.0
+ * Generated by: https://openapi-generator.tech
+ * Generator version: 7.14.0
+ */
+
+/**
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Please update the test case below to test the model.
+ */
+
+namespace OmsorgCoreClient\Test\Model;
+
+use PHPUnit\Framework\TestCase;
+
+/**
+ * PermissionActionTest Class Doc Comment
+ *
+ * @category    Class
+ * @description PermissionAction
+ * @package     OmsorgCoreClient
+ * @author      OpenAPI Generator team
+ * @link        https://openapi-generator.tech
+ */
+class PermissionActionTest extends TestCase
+{
+
+    /**
+     * Setup before running any test case
+     */
+    public static function setUpBeforeClass(): void
+    {
+    }
+
+    /**
+     * Setup before running each test case
+     */
+    public function setUp(): void
+    {
+    }
+
+    /**
+     * Clean up after running each test case
+     */
+    public function tearDown(): void
+    {
+    }
+
+    /**
+     * Clean up after running all test cases
+     */
+    public static function tearDownAfterClass(): void
+    {
+    }
+
+    /**
+     * Test "PermissionAction"
+     */
+    public function testPermissionAction()
+    {
+        // TODO: implement
+        self::markTestIncomplete('Not implemented');
+    }
+}