Volle Mindflux-App ins Deploy-Repo übernehmen

Ersetzt das Hello-World-Gerüst durch die vollständige Anwendung
(com.example.mindflux: 64 Klassen, Thymeleaf-Templates, Static-Assets,
Flyway V1–V6). Deploy-Infrastruktur (.gitea, Dockerfile) bleibt erhalten.

- pom: volle Abhängigkeiten (Security, Thymeleaf, JPA, Flyway), Spring Boot 3.4.4 / Java 17
- docker-compose: SPRING_DATASOURCE_* unverändert; App lauscht auf 8080
  (nginx -> mindflux:8080); Uploads-Volume; Admin-Passwörter via Gitea-Secrets
- Workflow: Deploy-Step injiziert MINDFLUX_ADMIN*_PASSWORD aus Secrets
- .dockerignore ergänzt; Hello-World (com.mindflux) und Test-Datei 'main' entfernt

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/main/resources/templates/admin/users/form.html

@@ -0,0 +1,67 @@
+<!DOCTYPE html>
+<html lang="de" data-theme="dark"
+      xmlns:th="http://www.thymeleaf.org"
+      xmlns:sec="https://www.thymeleaf.org/thymeleaf-extras-springsecurity6">
+<head>
+    <meta charset="UTF-8">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>Benutzer bearbeiten</title>
+    <link rel="stylesheet" href="/css/theme.css">
+    <script src="/js/theme.js"></script>
+</head>
+<body>
+
+<div class="mf-theme-float"><button class="mf-theme"></button></div>
+
+<div class="mf-container" style="max-width:560px">
+
+    <div class="mf-page-head">
+        <a th:href="@{/admin/users}" class="mf-back">⟵ Zurück zur Benutzerliste</a>
+    </div>
+
+    <header style="margin-bottom:1.4rem">
+        <div class="mf-eyebrow">Benutzer</div>
+        <h1 style="color:var(--heading); font-size:1.75rem; font-weight:800; margin-top:.35rem">✏️ Benutzer bearbeiten</h1>
+    </header>
+
+    <main>
+        <form th:action="@{/admin/users/save}" th:object="${user}" method="post" class="mf-panel">
+            <input type="hidden" th:field="*{id}" />
+
+            <div class="mf-field">
+                <label class="mf-label">Benutzername</label>
+                <input class="mf-input" type="text" th:field="*{username}" required/>
+            </div>
+
+            <div class="mf-field">
+                <label class="mf-label">Passwort</label>
+                <input class="mf-input" type="password" name="password" th:required="${user.id == null}" autocomplete="new-password"/>
+            </div>
+
+            <div class="mf-field">
+                <label class="mf-label">E-Mail</label>
+                <input class="mf-input" type="email" th:field="*{email}" required/>
+            </div>
+
+            <div class="mf-field">
+                <label class="mf-label">Rolle</label>
+                <input class="mf-input" type="text" th:field="*{role}" required/>
+            </div>
+
+            <button type="submit" class="mf-btn" style="margin-top:.4rem">Speichern</button>
+        </form>
+    </main>
+
+</div>
+
+<footer class="mf-footer">
+  <a href="#">Support</a>
+  <a href="#">Feedback</a>
+  <a href="#">Nutzungsbedingungen</a>
+  <a href="#">Richtlinien</a>
+  <a href="#">Datenschutz</a>
+  <a href="#">Impressum</a>
+</footer>
+
+</body>
+</html>