Add i18n support for French and German with browser language detection

templates/register.html

@@ -1,54 +1,54 @@
 {% extends "base.html" %}
-{% block title %}Register — Meal Tracker{% endblock %}
+{% block title %}{{ t('Register — Meal Tracker') }}{% endblock %}
 {% block content %}
 <div class="form-card register-card">
-    <h2>Create Account</h2>
+    <h2>{{ t('Create Account') }}</h2>
     <form method="POST">
-        <label for="username">Username</label>
+        <label for="username">{{ t('Username') }}</label>
         <input type="text" id="username" name="username" required autofocus>
 
-        <label for="password">Password</label>
+        <label for="password">{{ t('Password') }}</label>
         <input type="password" id="password" name="password" required>
 
-        <label for="confirm">Confirm Password</label>
+        <label for="confirm">{{ t('Confirm Password') }}</label>
         <input type="password" id="confirm" name="confirm" required>
 
         <fieldset class="household-section">
-            <legend>Household</legend>
+            <legend>{{ t('Household') }}</legend>
 
             <label class="radio-label">
                 <input type="radio" name="household_action" value="join" id="radio-join" checked>
-                Join an existing household
+                {{ t('Join an existing household') }}
             </label>
             <div id="join-block" class="household-block">
                 <select name="household_id" class="select-input">
-                    <option value="">— Select —</option>
+                    <option value="">{{ t('— Select —') }}</option>
                     {% for h in households %}
                     <option value="{{ h.id }}">{{ h.name }}</option>
                     {% endfor %}
                 </select>
                 {% if not households %}
-                <p class="hint">No households yet. Create one below!</p>
+                <p class="hint">{{ t('No households yet. Create one below!') }}</p>
                 {% endif %}
             </div>
 
             <label class="radio-label">
                 <input type="radio" name="household_action" value="create" id="radio-create"
                        {% if not households %}checked{% endif %}>
-                Create a new household
+                {{ t('Create a new household') }}
             </label>
             <div id="create-block" class="household-block">
                 <input type="text" name="new_household_name"
-                       placeholder="Household name (e.g. The Smiths)"
+                       placeholder="{{ t('Household name (e.g. The Smiths)') }}"
                        class="text-input">
-                <p class="hint">You'll be the admin of this household.</p>
+                <p class="hint">{{ t("You'll be the admin of this household.") }}</p>
             </div>
         </fieldset>
 
-        <button type="submit" class="btn btn-primary">Register</button>
+        <button type="submit" class="btn btn-primary">{{ t('Register') }}</button>
     </form>
     <p class="form-footer">
-        Already have an account? <a href="{{ url_for('auth.login') }}">Log in</a>
+        {{ t('Already have an account?') }} <a href="{{ url_for('auth.login') }}">{{ t('Log in') }}</a>
     </p>
 </div>