Closes P0 #5 from PARTIAL to RESOLVED. Sweeps the remaining 24 pages/api/** handlers that carried the identical scaffolded wildcard-CORS + OPTIONS preflight pattern (Brief 4 cleaned login + register; this finishes the job). Adds a blocking forbidden-cors-headers CI job modeled on forbidden-endpoints to lock the cleanup against future regression. 25 files changed (+29/-261). Local: lint 128 baseline, vitest 21/21, zero CORS matches, YAML valid. CI: Playwright smoke 3/3 in 3.3s against post-removal preview (login/verify flow still works), new forbidden-cors-headers job passes in 4s, all gates green. PR #19 architect-commit ec22b70, implementer-commit a843736.
da50d78406