[vadde]

Summary

This PR implements Requirement R-108 (MathWorks Simulink .slx / .mdl MBSE Ingestion) for the Omni-Graph engine, completing the MathWorks MBSE integration roadmap.

Key Architectural Deliverables

1. In-Memory Open Packaging Conventions (OPC) Archive Decompression (parse_slx):
   • Streams simulink/blockdiagram.xml directly in RAM with bounded buffer memory footprint (< 5MB) and zero temporary disk writes.
2. Streaming XML Parser (quick-xml):
   • Handles both Event::Start and Event::Empty tags for blocks, models, subsystems, lines, and property bindings.
3. Legacy Plain-Text .mdl Parser (parse_mdl):
   • Full topological parity for legacy structured block diagrams.
4. MBSE Graph Topology:
   • CONTAINS_BLOCK hierarchy for models and subsystems.
   • Blocks indexed by unique Simulink Identifier (SID).
   • SIGNAL_TO directed dataflow edges connecting port addresses (SID#out:port -> SID#in:port) including branched fanout topologies.
   • Cross-model REFERENCES_MODEL edges for ModelReference blocks.
   • High-degree broadcast line attenuation: Lines with > 50 fanouts (e.g. 28V power rail, CAN bus) are tagged DATAFLOW_BROADCAST to preserve community modularity clustering.
5. Full Pipeline Symmetry:
   • Integrated into both batch ingestion (execute_ingest) and incremental live watcher (reindex_file).
   • Transactional atomic swap with zero-delay community inference.
6. Tests & Parity:
   • 4 new unit tests (test_r108_*), 122/122 unit tests passing in 0.05s.
   • 0 Clippy warnings with -D warnings.
   • Quad-Parity maintained across Spec, STATUS.md, CONTEXT.md, and DEVLOG.md.