Fix JS syntax errors in tour_de_force.html; update type-contracts docs

Three literal newlines were embedded inside single-quoted JS string literals (join/split calls), causing a SyntaxError that prevented the DAG visualization from rendering. Replace with the escape sequence \n.

Also update docs/reference/type-contracts.md, docs/protocol/muse-protocol.md, and docs/architecture/muse-vcs.md to reflect the MergeResult fields added in the .museattributes implementation (applied_strategies, dimension_reports) and the repo_root keyword added to MuseDomainPlugin.merge(). Two new sections document AttributeRule and the MIDI dimension merge types.