FIX 1: Cloudflare Artifacts routes (wsAuth POST/GET /artifacts, /fork, /token)
were accidentally dropped when #618 modified router.go. Restored along with the
handler and client packages that were already on main (#595/#641) but missing
from this branch.
FIX 2: Stray `audh := handlers.NewAuditHandler()` / `wsAuth.GET("/audit", ...)` block
was added out-of-scope during #618 work. Removed — #594 (audit-ledger) is a
separate merged PR and its routes live on main independently.
Build: `go build ./...` clean. All 17 test packages pass.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>