fix(providers): remove Qwen provider support

Qwen OAuth flow (portal.qwen.ai) stopped working reliably; drop the
executor, registry entry, OAuth provider/service, token refresh
profile, usage handler, and related test coverage and baselines.

tests/unit/usage-dispatch.test.js

@@ -14,7 +14,7 @@ vi.mock("../../open-sse/utils/proxyFetch.js", () => ({
 const load = () => import("../../open-sse/services/usage.js");
 const SUPPORTED = [
   "github", "gemini-cli", "antigravity", "claude", "codex", "kiro",
-  "qoder", "qwen", "iflow", "ollama", "glm", "glm-cn",
+  "qoder", "iflow", "ollama", "glm", "glm-cn",
   "minimax", "minimax-cn", "vercel-ai-gateway", "grok-cli", "kimi",
   "deepseek",
 ];