Closes every deferred v1.4.45 audit Medium/Low + the W14 legacy-column cleanup. Three migrations required: 0076 Withings OAuth state, 0077 drop legacy consecutiveFailures, 0078 user.disableCoach. Run prisma migrate deploy BEFORE rolling the image (0078 is required by /api/auth/me). Tests 5093 → ~5170 (+76). 6-axis QA round complete. Full notes in CHANGELOG [1.4.47].