feat(orpd-217): add source date fields for tracking raw date inputs

Introduce `source_date_issued`, `source_date_modified`, and `source_date_valid` fields to retain unnormalized date inputs in cache and database models. This ensures raw date values are preserved alongside normalized versions for better traceability. Includes corresponding database migrations to support these additions.

app/cache/legislation.py

@@ -280,6 +280,8 @@ def _to_json(
             "date_issued": convert_date_string_to_obj(valid_sort_date),
             "date_modified": convert_date_string_to_obj(modified),
             "date_valid": valid_sort_date,
+            "source_date_modified": modified,
+            "source_date_valid": valid,
             "sort_date": valid_sort_date,
             "type": "Legislation",
         }

app/cache/public_gateway.py

@@ -138,6 +138,13 @@ def build_cache(self, config):
                     f"{inserted_document_count} / ({total_documents})..."
                 )
 
+                # Unnormalized date fields
+                row["source_date_issued"] = row.get("date_issued")
+
+                row["source_date_modified"] = row.get("date_modified")
+
+                row["source_date_valid"] = row.get("date_valid")
+
                 # Normalize the date fields
                 row["date_issued"] = convert_date_string_to_obj(
                     row.get("date_issued")

app/search/migrations/0002_dataresponsemodel_source_date_issued_and_more.py

@@ -0,0 +1,28 @@
+# Generated by Django 4.2.19 on 2025-02-27 13:05
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ("search", "0001_initial"),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name="dataresponsemodel",
+            name="source_date_issued",
+            field=models.TextField(blank=True, null=True),
+        ),
+        migrations.AddField(
+            model_name="dataresponsemodel",
+            name="source_date_modified",
+            field=models.TextField(blank=True, null=True),
+        ),
+        migrations.AddField(
+            model_name="dataresponsemodel",
+            name="source_date_valid",
+            field=models.TextField(blank=True, null=True),
+        ),
+    ]

app/search/models.py

@@ -61,6 +61,9 @@ class DataResponseModel(models.Model):
     date_issued = models.DateField(null=True, blank=True)
     date_modified = models.DateField(null=True, blank=True)
     date_valid = models.TextField(null=True, blank=True)
+    source_date_issued = models.TextField(null=True, blank=True)
+    source_date_modified = models.TextField(null=True, blank=True)
+    source_date_valid = models.TextField(null=True, blank=True)
     sort_date = models.DateField(null=True, blank=True)
     audience = models.TextField(null=True, blank=True)
     coverage = models.TextField(null=True, blank=True)