feat: Add Kilo Gateway provider (#20212)

* feat: Add Kilo Gateway provider

Add support for Kilo Gateway as a model provider, similar to OpenRouter.
Kilo Gateway provides a unified API that routes requests to many models
behind a single endpoint and API key.

Changes:
- Add kilocode provider option to auth-choice and onboarding flows
- Add KILOCODE_API_KEY environment variable support
- Add kilocode/ model prefix handling in model-auth and extra-params
- Add provider documentation in docs/providers/kilocode.md
- Update model-providers.md with Kilo Gateway section
- Add design doc for the integration

* kilocode: add provider tests and normalize onboard auth-choice registration

* kilocode: register in resolveImplicitProviders so models appear in provider filter

* kilocode: update base URL from /api/openrouter/ to /api/gateway/

* docs: fix formatting in kilocode docs

* fix: address PR review — remove kilocode from cacheRetention, fix stale model refs and CLI name in docs, fix TS2742

* docs: fix stale refs in design doc — Moltbot to OpenClaw, MoltbotConfig to OpenClawConfig, remove extra-params section, fix doc path

* fix: use resolveAgentModelPrimaryValue for AgentModelConfig union type

---------

Co-authored-by: Mark IJbema <mark@kilocode.ai>

src/commands/onboard-auth.credentials.ts

@@ -213,6 +213,7 @@ export const HUGGINGFACE_DEFAULT_MODEL_REF = "huggingface/deepseek-ai/DeepSeek-R
 export const TOGETHER_DEFAULT_MODEL_REF = "together/moonshotai/Kimi-K2.5";
 export const LITELLM_DEFAULT_MODEL_REF = "litellm/claude-opus-4-6";
 export const VERCEL_AI_GATEWAY_DEFAULT_MODEL_REF = "vercel-ai-gateway/anthropic/claude-opus-4.6";
+export const KILOCODE_DEFAULT_MODEL_REF = "kilocode/anthropic/claude-opus-4.6";
 
 export async function setZaiApiKey(key: string, agentDir?: string) {
   // Write to resolved agent dir so gateway finds credentials on startup.
@@ -372,3 +373,15 @@ export async function setMistralApiKey(key: string, agentDir?: string) {
     agentDir: resolveAuthAgentDir(agentDir),
   });
 }
+
+export async function setKilocodeApiKey(key: string, agentDir?: string) {
+  upsertAuthProfile({
+    profileId: "kilocode:default",
+    credential: {
+      type: "api_key",
+      provider: "kilocode",
+      key,
+    },
+    agentDir: resolveAuthAgentDir(agentDir),
+  });
+}