feat(migrations): add Django migration for DeletionRequest model

Created migration 1076_add_deletion_request.py to add the DeletionRequest model
to the database schema. This model tracks AI-initiated deletion requests that
require explicit user approval before any documents are deleted.

Migration includes:
- All model fields (created_at, updated_at, requested_by_ai, ai_reason, status, etc.)
- ManyToMany relationship with Document model
- Foreign keys to User model (user and reviewed_by)
- Custom indexes for common query patterns (status+user, created_at)
- Proper ordering and metadata

Fixes #10

Co-authored-by: dawnsystem <42047891+dawnsystem@users.noreply.github.com>

src/documents/migrations/1076_add_deletion_request.py

@@ -0,0 +1,148 @@
+# Generated manually for DeletionRequest model
+# Based on model definition in documents/models.py
+
+from django.conf import settings
+from django.db import migrations, models
+import django.db.models.deletion
+
+
+class Migration(migrations.Migration):
+    """
+    Add DeletionRequest model for AI-initiated deletion requests.
+    
+    This model tracks deletion requests that require user approval,
+    implementing the safety requirement from agents.md to ensure
+    no documents are deleted without explicit user consent.
+    """
+
+    dependencies = [
+        migrations.swappable_dependency(settings.AUTH_USER_MODEL),
+        ("documents", "1075_add_performance_indexes"),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name="DeletionRequest",
+            fields=[
+                (
+                    "id",
+                    models.BigAutoField(
+                        auto_created=True,
+                        primary_key=True,
+                        serialize=False,
+                        verbose_name="ID",
+                    ),
+                ),
+                (
+                    "created_at",
+                    models.DateTimeField(auto_now_add=True),
+                ),
+                (
+                    "updated_at",
+                    models.DateTimeField(auto_now=True),
+                ),
+                (
+                    "requested_by_ai",
+                    models.BooleanField(default=True),
+                ),
+                (
+                    "ai_reason",
+                    models.TextField(
+                        help_text="Detailed explanation from AI about why deletion is recommended"
+                    ),
+                ),
+                (
+                    "status",
+                    models.CharField(
+                        choices=[
+                            ("pending", "Pending"),
+                            ("approved", "Approved"),
+                            ("rejected", "Rejected"),
+                            ("cancelled", "Cancelled"),
+                            ("completed", "Completed"),
+                        ],
+                        default="pending",
+                        max_length=20,
+                    ),
+                ),
+                (
+                    "impact_summary",
+                    models.JSONField(
+                        default=dict,
+                        help_text="Summary of what will be affected by this deletion",
+                    ),
+                ),
+                (
+                    "reviewed_at",
+                    models.DateTimeField(blank=True, null=True),
+                ),
+                (
+                    "review_comment",
+                    models.TextField(
+                        blank=True,
+                        help_text="User's comment when reviewing",
+                    ),
+                ),
+                (
+                    "completed_at",
+                    models.DateTimeField(blank=True, null=True),
+                ),
+                (
+                    "completion_details",
+                    models.JSONField(
+                        default=dict,
+                        help_text="Details about the deletion execution",
+                    ),
+                ),
+                (
+                    "documents",
+                    models.ManyToManyField(
+                        help_text="Documents that would be deleted if approved",
+                        related_name="deletion_requests",
+                        to="documents.document",
+                    ),
+                ),
+                (
+                    "reviewed_by",
+                    models.ForeignKey(
+                        blank=True,
+                        help_text="User who reviewed and approved/rejected",
+                        null=True,
+                        on_delete=django.db.models.deletion.SET_NULL,
+                        related_name="reviewed_deletion_requests",
+                        to=settings.AUTH_USER_MODEL,
+                    ),
+                ),
+                (
+                    "user",
+                    models.ForeignKey(
+                        help_text="User who must approve this deletion",
+                        on_delete=django.db.models.deletion.CASCADE,
+                        related_name="deletion_requests",
+                        to=settings.AUTH_USER_MODEL,
+                    ),
+                ),
+            ],
+            options={
+                "verbose_name": "deletion request",
+                "verbose_name_plural": "deletion requests",
+                "ordering": ["-created_at"],
+            },
+        ),
+        # Add composite index for status + user (common query pattern)
+        migrations.AddIndex(
+            model_name="deletionrequest",
+            index=models.Index(
+                fields=["status", "user"],
+                name="del_req_status_user_idx",
+            ),
+        ),
+        # Add index for created_at (for chronological queries)
+        migrations.AddIndex(
+            model_name="deletionrequest",
+            index=models.Index(
+                fields=["created_at"],
+                name="del_req_created_idx",
+            ),
+        ),
+    ]