Retry GitHub solution sync on transient server errors (#8468)

Rescue Octokit::ServerError (covers BadGateway, InternalServerError,
ServiceUnavailable) in the sync commands and requeue the job after 30
seconds, matching the existing requeue pattern used for Discord rate
limits.

Closes #8457

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

Author: iHiD

app/commands/user/github_solution_syncer/sync_everything.rb

@@ -17,6 +17,8 @@ def call
       end
     rescue GithubApp::InstallationNotFoundError
       # noop - installation may have been removed or GitHub may be having issues
+    rescue Octokit::ServerError
+      requeue_job!(30.seconds)
     end
 
     def sync_everything(branch_name, token = nil)

app/commands/user/github_solution_syncer/sync_iteration.rb

@@ -20,6 +20,8 @@ def call
       end
     rescue GithubApp::InstallationNotFoundError
       # noop - installation may have been removed or GitHub may be having issues
+    rescue Octokit::ServerError
+      requeue_job!(30.seconds)
     end
 
     private

app/commands/user/github_solution_syncer/sync_solution.rb

@@ -17,6 +17,8 @@ def call
       end
     rescue GithubApp::InstallationNotFoundError
       # noop - installation may have been removed or GitHub may be having issues
+    rescue Octokit::ServerError
+      requeue_job!(30.seconds)
     end
 
     private

app/commands/user/github_solution_syncer/sync_track.rb

@@ -17,6 +17,8 @@ def call
       end
     rescue GithubApp::InstallationNotFoundError
       # noop - installation may have been removed or GitHub may be having issues
+    rescue Octokit::ServerError
+      requeue_job!(30.seconds)
     end
 
     private

test/commands/user/github_solution_syncer/sync_everything_test.rb

@@ -11,5 +11,18 @@ class SyncEverythingTest < ActiveSupport::TestCase
       # Should not raise
       User::GithubSolutionSyncer::SyncEverything.(user)
     end
+
+    test "requeues on server error" do
+      user = create(:user)
+      create(:user_github_solution_syncer, user:)
+
+      CreatePullRequest.stubs(:call).raises(Octokit::ServerError)
+
+      Mocha::Configuration.override(stubbing_non_existent_method: :allow) do
+        cmd = User::GithubSolutionSyncer::SyncEverything.new(user)
+        cmd.expects(:requeue_job!).with(30.seconds)
+        cmd.()
+      end
+    end
   end
 end

test/commands/user/github_solution_syncer/sync_iteration_test.rb

@@ -16,5 +16,23 @@ class SyncIterationTest < ActiveSupport::TestCase
       # Should not raise
       User::GithubSolutionSyncer::SyncIteration.(iteration)
     end
+
+    test "requeues on server error" do
+      user = create(:user)
+      track = create(:track, slug: "ruby")
+      exercise = create(:practice_exercise, track:, slug: "two-fer")
+      solution = create(:practice_solution, user:, exercise:)
+      submission = create(:submission, solution:)
+      iteration = create(:iteration, user:, solution:, submission:)
+      create(:user_github_solution_syncer, user:)
+
+      CreatePullRequest.stubs(:call).raises(Octokit::ServerError)
+
+      Mocha::Configuration.override(stubbing_non_existent_method: :allow) do
+        cmd = User::GithubSolutionSyncer::SyncIteration.new(iteration)
+        cmd.expects(:requeue_job!).with(30.seconds)
+        cmd.()
+      end
+    end
   end
 end

test/commands/user/github_solution_syncer/sync_solution_test.rb

@@ -14,5 +14,21 @@ class SyncSolutionTest < ActiveSupport::TestCase
       # Should not raise
       User::GithubSolutionSyncer::SyncSolution.(solution)
     end
+
+    test "requeues on server error" do
+      user = create(:user)
+      track = create(:track, slug: "ruby")
+      exercise = create(:practice_exercise, track:, slug: "two-fer")
+      solution = create(:practice_solution, user:, exercise:)
+      create(:user_github_solution_syncer, user:)
+
+      CreatePullRequest.stubs(:call).raises(Octokit::ServerError)
+
+      Mocha::Configuration.override(stubbing_non_existent_method: :allow) do
+        cmd = User::GithubSolutionSyncer::SyncSolution.new(solution)
+        cmd.expects(:requeue_job!).with(30.seconds)
+        cmd.()
+      end
+    end
   end
 end

test/commands/user/github_solution_syncer/sync_track_test.rb

@@ -13,5 +13,20 @@ class SyncTrackTest < ActiveSupport::TestCase
       # Should not raise
       User::GithubSolutionSyncer::SyncTrack.(user_track)
     end
+
+    test "requeues on server error" do
+      user = create(:user)
+      track = create(:track, slug: "ruby")
+      user_track = create(:user_track, user:, track:)
+      create(:user_github_solution_syncer, user:)
+
+      CreatePullRequest.stubs(:call).raises(Octokit::ServerError)
+
+      Mocha::Configuration.override(stubbing_non_existent_method: :allow) do
+        cmd = User::GithubSolutionSyncer::SyncTrack.new(user_track)
+        cmd.expects(:requeue_job!).with(30.seconds)
+        cmd.()
+      end
+    end
   end
 end