Move chat pipeline validation, circuit breaker execution, proxy
resolution, logging, and session header handling into dedicated
helpers to keep the SSE handler smaller and easier to verify.
Also fix shared API option precedence, rebuild skill version caches
after deletions, ignore api.trycloudflare.com false positives, and
add rate-limit manager test flush/reset hooks for deterministic
coverage.
Expand integration and unit coverage across chat routing, auth,
cloud sync, skills, executors, streaming, DB helpers, proxy handling,
and provider/model utilities.
diegosouzapw