5c2f48535f
Renames `compute_degrees` to `compute_degrees_and_mark_starts` across the De Bruijn graph and partitioner layers to consolidate degree calculation and start-node flagging. Introduces safe neighbor iteration methods and a debug validation block to verify graph consistency. Refactors unitig extraction to use sequential execution with a `Mutex` for safe error propagation. Fixes malformed and duplicated method calls, adds auto-generation of missing `meta.json` files, and ensures persistent matrix builders are explicitly closed to finalize metadata.