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/agents/transcript-policy.ts

@@ -91,7 +91,7 @@ export function resolveTranscriptPolicy(params: {
     !OPENAI_COMPAT_TURN_MERGE_EXCLUDED_PROVIDERS.has(provider);
   const isMistral = isMistralModel({ provider, modelId });
   const isOpenRouterGemini =
-    (provider === "openrouter" || provider === "opencode") &&
+    (provider === "openrouter" || provider === "opencode" || provider === "kilocode") &&
     modelId.toLowerCase().includes("gemini");
   const isCopilotClaude = provider === "github-copilot" && modelId.toLowerCase().includes("claude");