feat(presets): add RelaxyCode provider presets

Add RelaxyCode as a new third-party provider with support for:
- Claude Code preset (Anthropic native protocol)
- Codex preset (gpt-5.5 model)
- Claude Desktop preset (direct mode with passthrough routes)

RelaxyCode is an enterprise-grade AI programming platform providing
unified access to Claude Code, Codex, and Gemini CLI models.

src/config/codexProviderPresets.ts

@@ -216,6 +216,19 @@ requires_openai_auth = true`,
     partnerPromotionKey: "runapi",
     icon: "runapi",
   },
+  {
+    name: "RelaxyCode",
+    websiteUrl: "https://www.relaxycode.com",
+    apiKeyUrl: "https://www.relaxycode.com/register",
+    category: "third_party",
+    auth: generateThirdPartyAuth(""),
+    config: generateThirdPartyConfig(
+      "relaxycode",
+      "https://www.relaxycode.com/v1",
+      "gpt-5.5",
+    ),
+    icon: "claude",
+  },
   {
     name: "Cubence",
     websiteUrl: "https://cubence.com",