The burden block of the certified QC report (design memo `vignettes/articles/devlog-2026-10-04-M4-02b-qc-memo.qmd` section 3, as implemented in `R/ms-qc-report.R:95-105` at the time this surface was factored out), exposed as its own addressable surface: one row per sample with the total burden, its base-10 log and the house-declared burden class (dead/low/standard/high over the frozen `.ms_qc_defaults` constants). The values delegate to the same computation core as [ms_qc_report()] – column-for-column identical, never a second implementation.