feature: issuse_certicate, tests views

CHANGELOG.md

@@ -32,6 +32,9 @@ Follows [Keep a Changelog](https://keepachangelog.com/en/1.0.0/) and [Semantic V
 - Cursor-based pagination for receipt listing endpoint (`GET /api/receipts/`). Supports
   configurable page sizes via `?page_size=N` parameter (max 100 items).
 - Receipt lines are now included in paginated receipt list responses via `prefetch_related()`.
+- Certificate renewal endpoint (`IssueCertificateView`) - POST endpoint to issue/renew
+  device certificates using the `CertificateService.issue_certificate()` flow. Returns
+  success or detailed error responses when certificate issuance fails.
 
 ### Changed
 - Monetary fields in models now use `DecimalField` instead of `FloatField` for precise financial

fiscguy/tests/conftest.py

@@ -7,6 +7,8 @@ def pytest_configure():
         settings.configure(
             INSTALLED_APPS=[
                 "django.contrib.contenttypes",
+                "django.contrib.auth",
+                "rest_framework",
                 "fiscguy",
             ],
             DATABASES={
@@ -16,6 +18,12 @@ def pytest_configure():
                 }
             },
             SECRET_KEY="fake-key-for-tests",
+            ROOT_URLCONF="fiscguy.urls",
+            DEFAULT_AUTO_FIELD="django.db.models.BigAutoField",
+            REST_FRAMEWORK={
+                "DEFAULT_AUTHENTICATION_CLASSES": [],
+                "DEFAULT_PERMISSION_CLASSES": [],
+            },
         )
         django.setup()