ADR 0004: .loreleyignore for embedding scope

Date: 2026-01-06

Context: Users need a way to control which repository files participate in embeddings without changing Git tracking rules. Decision: Support a repository-root .loreleyignore file and parse it with gitignore semantics via pathspec.gitignore.GitIgnoreSpec. Details: In scheduler runs, ignore rules are pinned at process startup from the configured root commit and stored in Settings.mapelites_repo_state_ignore_text for the lifetime of the scheduler process. Runtime repo-state embeddings use the pinned matcher and do not consult per-commit or working-tree ignore files. Details: Apply .gitignore rules first, then .loreleyignore rules, so .loreleyignore may override via negation (!pattern). Constraints: Matching remains root-only (no nested .gitignore files and no global excludes). Consequences: Repo-state eligibility is stable for an experiment, removing dynamic-ignore edge cases from incremental-only ingestion.