chore: 将后端移动到 api/ 目录，准备合并为单仓库

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

api/prompt/migrations/0001_initial.py

@@ -0,0 +1,50 @@
+# Generated by Django 6.0.1 on 2026-03-04 11:01
+
+import django.db.models.deletion
+import django_extensions.db.fields
+import uuid
+from django.conf import settings
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    initial = True
+
+    dependencies = [
+        ('task', '0005_alter_task_options_alter_task_display_and_more'),
+        migrations.swappable_dependency(settings.AUTH_USER_MODEL),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name='Conversation',
+            fields=[
+                ('created', django_extensions.db.fields.CreationDateTimeField(auto_now_add=True, verbose_name='created')),
+                ('modified', django_extensions.db.fields.ModificationDateTimeField(auto_now=True, verbose_name='modified')),
+                ('id', models.UUIDField(default=uuid.uuid4, editable=False, primary_key=True, serialize=False)),
+                ('is_active', models.BooleanField(default=True, verbose_name='是否活跃')),
+                ('task', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='conversations', to='task.task')),
+                ('user', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='conversations', to=settings.AUTH_USER_MODEL)),
+            ],
+            options={
+                'ordering': ('-created',),
+            },
+        ),
+        migrations.CreateModel(
+            name='Message',
+            fields=[
+                ('id', models.BigAutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('role', models.CharField(max_length=10)),
+                ('content', models.TextField()),
+                ('code_html', models.TextField(blank=True, null=True)),
+                ('code_css', models.TextField(blank=True, null=True)),
+                ('code_js', models.TextField(blank=True, null=True)),
+                ('created', models.DateTimeField(auto_now_add=True)),
+                ('conversation', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='messages', to='prompt.conversation')),
+            ],
+            options={
+                'ordering': ('created',),
+            },
+        ),
+    ]