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/capabilities.js

@@ -258,6 +258,12 @@ export const PATTERN_CAPABILITIES = [
   { pattern: "*gpt-3.5*",       caps: { contextWindow: 16385, maxOutput: 4096 } },
   { pattern: "*gpt-oss*",       caps: { reasoning: true, thinkingFormat: "openai", contextWindow: 128000 } },
 
+  // ── Cline free tier: Upstage Solar Pro + LongCat (agentic coding models;
+  // windows unverified — 200K/32K conservative, same as laguna:free).
+  // NOTE: placed before the o-series catch-alls — "solar-pro4" contains "o4".
+  { pattern: "*solar-pro*",     caps: { reasoning: true, thinkingFormat: "openai", contextWindow: 200000, maxOutput: 32000 } },
+  { pattern: "*longcat*",       caps: { reasoning: true, thinkingFormat: "openai", contextWindow: 200000, maxOutput: 32000 } },
+
   // ── OpenAI o-series (reasoning, vision) ──────────────────────────
   { pattern: "*o1-mini*",       caps: { reasoning: true, thinkingFormat: "openai", contextWindow: 128000 } },
   { pattern: "*o1*",            caps: { vision: true, reasoning: true, thinkingFormat: "openai", contextWindow: 200000, maxOutput: 100000 } },