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/cli/program/register.onboard.ts

@@ -133,6 +133,7 @@ export function registerOnboardCommand(program: Command) {
           openaiApiKey: opts.openaiApiKey as string | undefined,
           mistralApiKey: opts.mistralApiKey as string | undefined,
           openrouterApiKey: opts.openrouterApiKey as string | undefined,
+          kilocodeApiKey: opts.kilocodeApiKey as string | undefined,
           aiGatewayApiKey: opts.aiGatewayApiKey as string | undefined,
           cloudflareAiGatewayAccountId: opts.cloudflareAiGatewayAccountId as string | undefined,
           cloudflareAiGatewayGatewayId: opts.cloudflareAiGatewayGatewayId as string | undefined,