Apply composite tier ordering to top-level combo steps and direct
targets so priority and round-robin strategies follow the configured
defaultTier to fallbackTier chain before using remaining steps.
Add defensive config parsing helpers, regression tests for composite
tier ordering, and documentation updates for the structured combo
builder, quota-aware P2C, and combo target health.
Allow chat core callers to disable the emergency fallback path during
routed retries and expose proxy cache reset helpers for deterministic
state handling.
Add regression coverage for chat routing edge cases, combo strategies,
stream utilities, cursor SSE termination, and JSON-to-SQLite db
migration behavior.
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.
