Add admin features, user profile management, and generation capabilities

- Implemented admin dashboard with user management features including role assignment and deletion.
- Added user profile page for updating email and password.
- Created separate routes and templates for text, image, and video generation with appropriate forms.
- Enhanced navigation with dropdown for generation options and loading overlay for better user experience.
- Introduced comprehensive error handling and user feedback through alerts.
- Updated styles for improved UI consistency and responsiveness.

Co-authored-by: Copilot <copilot@github.com>

frontend/app/templates/profile.html

@@ -0,0 +1,43 @@
+{% extends "base.html" %} {% block title %}Profile — AI Allucanget{% endblock %}
+{% block content %}
+<div class="card">
+  <h1>Your Profile</h1>
+
+  <h2 class="section-title" style="margin-top: 0">Account details</h2>
+  <p class="text-muted" style="font-size: 0.875rem; margin-bottom: 1.5rem">
+    Current email:
+    <strong style="color: var(--text)">{{ user.get('email', '') }}</strong>
+    &nbsp;·&nbsp; Role:
+    <span class="role-badge role-{{ user.get('role','user') }}"
+      >{{ user.get('role', 'user') }}</span
+    >
+  </p>
+
+  <h2 class="section-title">Update email</h2>
+  <form method="post">
+    <label for="email">New email</label>
+    <input
+      id="email"
+      name="email"
+      type="email"
+      placeholder="{{ user.get('email', '') }}"
+    />
+    <input type="hidden" name="password" value="" />
+    <button type="submit">Save email</button>
+  </form>
+
+  <h2 class="section-title" style="margin-top: 2rem">Change password</h2>
+  <form method="post">
+    <label for="password">New password</label>
+    <input
+      id="password"
+      name="password"
+      type="password"
+      placeholder="Enter new password"
+      minlength="8"
+    />
+    <input type="hidden" name="email" value="" />
+    <button type="submit">Save password</button>
+  </form>
+</div>
+{% endblock %}