Add phase 4: AI cleanup and photo/text import via OpenAI

- recipes/ai.py: Chat Completions with strict JSON schema (Structured
  Outputs), Pydantic re-validation, plausibility clamping, prompt treats
  input as data only
- "Mit KI aufbereiten" on create/edit form returns an editable draft
- Import page: photo/screenshot (vision, downscaled JPEG, not stored) and
  pasted text; drafts pre-fill the recipe form with a preview
- Clear UI messages for timeout, rate limit, quota, auth, model and
  connection errors; without OPENAI_API_KEY AI features show a notice
- Optional per-user and global daily AI limits (default unlimited)
- Tests for response parsing, schema strictness, error mapping, views

Co-Authored-By: Claude Opus 5.5 <[email protected]>

templates/recipes/_ai_disabled.html

@@ -0,0 +1 @@
+<p class="msg msg-warning">Die KI-Funktionen sind nicht eingerichtet (kein <code>OPENAI_API_KEY</code>). Alles andere funktioniert normal – du kannst Rezepte von Hand eintragen.</p>

templates/recipes/_draft_preview.html

@@ -0,0 +1,23 @@
+<div class="msg msg-warning draft-notice">
+  <strong>{{ draft_notice|default:"KI-Entwurf" }} – bitte prüfen.</strong>
+  Noch nichts ist gespeichert. Korrigiere die Felder unten bei Bedarf und tippe dann auf „Speichern“.
+</div>
+{% if ai_draft %}
+<details class="card preview" open>
+  <summary><strong>Vorschau: {{ ai_draft.title|default:"Ohne Titel" }}</strong></summary>
+  {% if ai_draft.ingredients %}
+  <h3>Zutaten</h3>
+  <ul class="ingredients">
+    {% for ing in ai_draft.ingredients %}
+    <li><span class="amount">{% if ing.amount is not None %}{{ ing.amount|floatformat:"-2" }}{% if ing.amount_max is not None %}–{{ ing.amount_max|floatformat:"-2" }}{% endif %}{% endif %} {{ ing.unit }}</span>
+      <span>{% if ing.group %}<span class="muted">{{ ing.group }}: </span>{% endif %}{{ ing.name }}{% if ing.note %}<span class="muted">, {{ ing.note }}</span>{% endif %}</span></li>
+    {% endfor %}
+  </ul>
+  {% endif %}
+  {% if ai_draft.steps %}
+  <h3>Zubereitung</h3>
+  <ol class="steps">{% for step in ai_draft.steps %}<li>{{ step }}</li>{% endfor %}</ol>
+  {% endif %}
+  {% if ai_draft.tags %}<p class="chips">{% for tag in ai_draft.tags %}<span class="chip">#{{ tag }}</span>{% endfor %}</p>{% endif %}
+</details>
+{% endif %}

templates/recipes/form.html

@@ -3,17 +3,19 @@
 {% block content %}
 <h1>{% if is_new %}Neues Rezept{% else %}Rezept bearbeiten{% endif %}</h1>
 
-{% block before_form %}{% endblock %}
+{% if draft_notice or ai_draft %}{% include "recipes/_draft_preview.html" %}{% endif %}
 
-<form method="post" enctype="multipart/form-data" class="card recipe-form" novalidate>
+<form method="post"{% if form_action %} action="{{ form_action }}"{% endif %} enctype="multipart/form-data" class="card recipe-form" novalidate>
   {% csrf_token %}
   {% include "form_fields.html" %}
-  {% block form_buttons %}
   <div class="form-buttons">
     <button type="submit" class="button">Speichern</button>
+    {% if ai_enabled %}
+    <button type="submit" name="ai" value="1" class="button secondary" data-busy-text="KI arbeitet …">✨ Mit KI aufbereiten</button>
+    {% endif %}
     <a class="button secondary" href="{% if recipe %}{% url 'recipes:detail' recipe.pk %}{% else %}{% url 'recipes:list' %}{% endif %}">Abbrechen</a>
   </div>
-  {% endblock %}
+  {% if ai_enabled %}<p class="muted small">„Mit KI aufbereiten“ strukturiert deine Eingaben (Zutaten, Schritte, Tags) als Entwurf. Fotos danach auswählen – sie werden dabei nicht übernommen.</p>{% endif %}
 </form>
 
 {% if recipe and images %}

templates/recipes/import.html

@@ -0,0 +1,37 @@
+{% extends "base.html" %}
+{% block title %}Rezept importieren{% endblock %}
+{% block content %}
+<h1>Rezept importieren</h1>
+<p class="muted">Das Ergebnis ist immer ein Entwurf, den du prüfst und erst dann speicherst.</p>
+
+{% block link_import %}{% endblock %}
+
+<section class="card">
+  <h2>📷 Foto oder Screenshot</h2>
+  {% if ai_enabled %}
+  <form method="post" action="{% url 'recipes:import_photo' %}" enctype="multipart/form-data" novalidate>
+    {% csrf_token %}
+    {% with form=photo_form %}{% include "form_fields.html" %}{% endwith %}
+    <p class="muted small">Die Bilder werden zur Auswertung an OpenAI geschickt und nicht gespeichert.</p>
+    <button type="submit" class="button" data-busy-text="KI liest das Rezept …">Rezept erkennen</button>
+  </form>
+  {% else %}
+  {% include "recipes/_ai_disabled.html" %}
+  {% endif %}
+</section>
+
+<section class="card">
+  <h2>📝 Text einfügen</h2>
+  {% if ai_enabled %}
+  <form method="post" action="{% url 'recipes:import_text' %}" novalidate>
+    {% csrf_token %}
+    {% with form=text_form %}{% include "form_fields.html" %}{% endwith %}
+    <button type="submit" class="button" data-busy-text="KI bereitet auf …">Mit KI aufbereiten</button>
+  </form>
+  {% else %}
+  {% include "recipes/_ai_disabled.html" %}
+  {% endif %}
+</section>
+
+<p><a href="{% url 'recipes:create' %}">Oder ganz von Hand eintragen →</a></p>
+{% endblock %}

templates/recipes/list.html

@@ -3,7 +3,10 @@
 {% block content %}
 <div class="page-head">
   <h1>Rezepte</h1>
-  <a class="button" href="{% url 'recipes:create' %}">+ Neu</a>
+  <div class="head-actions">
+    <a class="button secondary" href="{% url 'recipes:import' %}">Import</a>
+    <a class="button" href="{% url 'recipes:create' %}">+ Neu</a>
+  </div>
 </div>
 
 <form method="get" class="search" role="search">