Stability checkpoint stable-v1.0.21 (UI) — Phase B-6 + Phase C combined wave: dashboard.component split (1022→713 ts via dashboard-types + dashboard-topology-data extraction; 1291→59 scss via 8 Sass partials). Phase C ESLint flip warn→error on 6 size/complexity rules (max-lines 700, max-lines-per-function 100, complexity 15, max-params 6, max-depth 4, max-nested-callbacks 4) — regressions now red CI errors. Two legitimate complexity violations (KeyboardService.onKeyDown, TelemetryService.push) carry inline disables with documented reason. Mobile @media safety-net added to 6 components missing one (settings/audit/pipelines/activity/database/incident-anatomy). File-length hygiene wave fully self-enforcing. Post-merge main pipeline #371 SUCCESS on 0892ca2.