This skill should be used when the user says "batch merge", "merge batch", "arness batch merge", "arn-code-batch-merge", "merge all PRs", "merge batch PRs", "merge the batch", "merge implemented features", "batch merge PRs", "merge open PRs", "merge all feature PRs", "combine batch PRs", "land the batch", "land all PRs", or wants to discover open batch implementation PRs, analyze them for conflicts, determine an optimal merge order, and execute merges with user-guided conflict resolution. This skill is typically invoked after arn-code-batch-implement completes and chains to arn-code-batch-simplify upon completion.