feat(providers): add Cline free-tier models and sync Freebuff catalog

- Cline: 6 free models, cline-cli product headers, API-key auth,
  {data} envelope unwrap, workos: prefix handling
- Freebuff: muse-spark 1.3 → 1.2 (upstream withdrawal 2026-09-07),
  DeepSeek V4.1 Flash rename

open-sse/providers/registry/clinepass.js

@@ -26,6 +26,9 @@ export default {
       combined: true,
       header: "Authorization",
       scheme: "bearer",
+      // Hook owns Authorization: workos:-prefixed OAuth vs plain API key
+      // (a merged token can't express both) — see applyAuth.
+      preserveHookAuth: true,
       hooks: [
         "clineHeaders",
       ],