DEV: ensure rebaking works even when some users have inconsistent data (#30261)

* DEV: add db consistency check for UserEmail

* DEV: add db consistency check for UserAvatar

* DEV: ignore inconsistent data related to user avatars when deciding whether to rebake old posts


Co-authored-by: Alan Guo Xiang Tan <gxtan1990@gmail.com>

---------

Co-authored-by: Alan Guo Xiang Tan <gxtan1990@gmail.com>

spec/models/user_email_spec.rb

@@ -63,4 +63,26 @@ RSpec.describe UserEmail do
       expect(user.user_emails.count).to eq 3
     end
   end
+
+  describe ".ensure_consistency!" do
+    context "when some users have no primary emails" do
+      it "creates primary emails for the users without a primary email" do
+        user_with_primary_email = Fabricate(:user)
+        user_without_primary_email = Fabricate(:user)
+        user_without_any_email = Fabricate(:user)
+
+        user_without_primary_email.primary_email.update_column(:primary, false)
+        user_without_any_email.user_emails.delete_all
+        original_email_of_user_with_primary_email = user_with_primary_email.primary_email.email
+
+        described_class.ensure_consistency!
+
+        expect(user_without_primary_email.reload.primary_email).to be_present
+        expect(user_without_any_email.reload.primary_email).to be_present
+        expect(
+          user_with_primary_email.reload.primary_email.email,
+        ).to eq original_email_of_user_with_primary_email
+      end
+    end
+  end
 end