test: test files named by their topic, one file per topic

- console settings were split over four files; who sees the form, the
  listen address, and the settings themselves are test_console_settings,
  and who may open a console is test_console_access;
- the three template files are test_templates;
- the quota lock test joins test_quota;
- accounts' test_security_fixes held two topics: the SSH key tests are
  test_ssh_keys, the owner-row delete redirect is in test_views;
- instances' test_security_mutations, who may change a VM, is
  test_permissions.
The suite runs the same 2097 tests.

accounts/tests/test_ssh_keys.py

@@ -0,0 +1,35 @@
+"""A user's SSH keys: they go with the user, and a key is valid with or without a comment."""
+
+from django.contrib.auth import get_user_model
+from django.test import TestCase
+
+from accounts.models import UserSSHKey
+from accounts.utils import validate_ssh_key
+
+
+class SshKeyTestCase(TestCase):
+    def test_ssh_key_cascade_deletion(self):
+        user = get_user_model().objects.create_user(username="sec_acc_user", password="password")
+        key = UserSSHKey.objects.create(
+            user=user,
+            keyname="my-key",
+            keypublic="ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIGabcdef123456 test@example.com",
+        )
+        self.assertTrue(UserSSHKey.objects.filter(id=key.id).exists())
+
+        # When user is deleted, key should be deleted via CASCADE (not left orphan)
+        user.delete()
+        self.assertFalse(UserSSHKey.objects.filter(id=key.id).exists())
+
+    def test_validate_ssh_key_supports_keys_with_and_without_comment(self):
+        rsa_base = "ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAAAgQC6OOdbfv27QVnSC6sKxGaHb6YFc+3gxCkyVR3cTSXE/n5BEGf8aOgBpepULWa1RZfxYHY14PlKULDygdXSdrrR2kNSwoKz/Oo4d+3EE92L7ocl1+djZbptzgWgtw1OseLwbFik+iKlIdqPsH+IUQvX7yV545ZQtAP8Qj1R+uCqkw=="
+        # Key with comment
+        key_with_comment = f"{rsa_base} test@test"
+        self.assertTrue(validate_ssh_key(key_with_comment))
+
+        # Key without comment
+        key_without_comment = rsa_base
+        self.assertTrue(validate_ssh_key(key_without_comment))
+
+        # Invalid key
+        self.assertFalse(validate_ssh_key("not a valid key string"))