gateway: direct Kimi For Coding provider adapter (api.kimi.com)

Wires kimi-for-coding (Kimi K2.6 underneath) as a first-class /v1/chat
provider so consumers can target it via {provider:"kimi"} or model
prefix kimi/<model>. Bypasses the upstream-broken kimi-k2:1t on Ollama
Cloud and the rate-limited moonshotai/kimi-k2.6 path through OpenRouter.

Adapter shape mirrors openrouter.rs (OpenAI-compatible Chat Completions).
Differences from generic OpenAI providers:

- api.kimi.com is a SEPARATE account system from api.moonshot.ai and
  api.moonshot.cn. sk-kimi-* keys are NOT interchangeable across them.
- Endpoint is User-Agent-gated to "approved" coding agents (Kimi CLI,
  Claude Code, Roo Code, Kilo Code, ...). Requests from generic clients
  return 403 access_terminated_error. Adapter sends User-Agent:
  claude-code/1.0.0. Per Moonshot TOS this is a tampering-class action
  that may result in seat suspension; J authorized 2026-04-27 with
  awareness of the risk.
- kimi-for-coding is a reasoning model — reasoning_content counts
  against max_tokens. Default 800-token budget yields empty visible
  content with finish_reason=length. Code-review workloads need
  max_tokens >= 1500.
- Default 600s upstream timeout (vs 180s for openrouter.rs) — code
  audits with full file context legitimately take 3-5 minutes.
  Override via KIMI_TIMEOUT_SECS env.

Key handling:
- /etc/lakehouse/kimi.env (0600 root) loaded via systemd EnvironmentFile
- KIMI_API_KEY env first, then file scrape as fallback
- /etc/systemd/system/lakehouse.service NOT included in this commit
  (system file outside repo); operator must add EnvironmentFile=-
  /etc/lakehouse/kimi.env to the lakehouse.service unit

NOT in scrum_master_pipeline LADDER. The 9-rung ladder is for
unattended automatic recovery; placing Kimi there would hammer a
TOS-gated endpoint with hostility-policy potential. Kimi is
addressable via /v1/chat for explicit invocations only — auditor
integration in a follow-up commit.

Verification:
  cargo check -p gateway --tests          compiles
  curl /v1/chat provider=kimi             200 OK, content="PONG"
  curl /v1/chat model="kimi/kimi-for-coding"  200 OK (prefix routing)
  Kimi audit on distillation last-week    7/7 grounded findings
                                          (reports/kimi/audit-last-week-full.md)

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

crates/gateway/src/v1/mod.rs

@@ -16,6 +16,7 @@ pub mod ollama_cloud;
 pub mod openrouter;
 pub mod gemini;
 pub mod claude;
+pub mod kimi;
 pub mod langfuse_trace;
 pub mod mode;
 pub mod respond;
@@ -53,6 +54,12 @@ pub struct V1State {
     /// `claude::resolve_claude_key()`. None = provider="claude" calls
     /// 503. Phase 40 deliverable.
     pub claude_key: Option<String>,
+    /// Kimi For Coding (api.kimi.com) bearer token — direct provider
+    /// for `kimi-for-coding`. Used when Ollama Cloud's `kimi-k2:1t` is
+    /// upstream-broken. Loaded at startup via `kimi::resolve_kimi_key()`
+    /// from `KIMI_API_KEY` env or `/etc/lakehouse/kimi.env`. None =
+    /// provider="kimi" calls 503.
+    pub kimi_key: Option<String>,
     /// Phase 40 early deliverable — Langfuse client. None = tracing
     /// disabled (keys missing or container unreachable). Traces are
     /// fire-and-forget: never block the response path.
@@ -224,6 +231,9 @@ fn resolve_provider(req: &ChatRequest) -> (String, String) {
     if let Some(rest) = req.model.strip_prefix("claude/") {
         return ("claude".to_string(), rest.to_string());
     }
+    if let Some(rest) = req.model.strip_prefix("kimi/") {
+        return ("kimi".to_string(), rest.to_string());
+    }
     // Bare `vendor/model` shape (e.g. `x-ai/grok-4.1-fast`,
     // `moonshotai/kimi-k2`, `openai/gpt-oss-120b:free`) → OpenRouter.
     // This makes the gateway a drop-in OpenAI-compatible middleware:
@@ -316,6 +326,12 @@ mod resolve_provider_tests {
         let r = mk_req(None, "claude/claude-3-5-sonnet-latest");
         assert_eq!(resolve_provider(&r), ("claude".into(), "claude-3-5-sonnet-latest".into()));
     }
+
+    #[test]
+    fn kimi_prefix_infers_and_strips() {
+        let r = mk_req(None, "kimi/kimi-for-coding");
+        assert_eq!(resolve_provider(&r), ("kimi".into(), "kimi-for-coding".into()));
+    }
 }
 
 async fn chat(
@@ -403,10 +419,24 @@ async fn chat(
                 .map_err(|e| (StatusCode::BAD_GATEWAY, format!("claude: {e}")))?;
             (r, "claude".to_string())
         }
+        "kimi" => {
+            // Direct Kimi For Coding provider — bypasses Ollama Cloud's
+            // upstream-broken kimi-k2:1t and OpenRouter's rate-limited
+            // moonshotai/kimi-k2.6. Uses sk-kimi-* keys from the Kimi
+            // membership console.
+            let key = state.kimi_key.as_deref().ok_or((
+                StatusCode::SERVICE_UNAVAILABLE,
+                "KIMI_API_KEY not configured".to_string(),
+            ))?;
+            let r = kimi::chat(key, &*req_for_adapter)
+                .await
+                .map_err(|e| (StatusCode::BAD_GATEWAY, format!("kimi: {e}")))?;
+            (r, "kimi".to_string())
+        }
         other => {
             return Err((
                 StatusCode::BAD_REQUEST,
-                format!("unknown provider '{other}' — supported: ollama, ollama_cloud, openrouter, gemini, claude"),
+                format!("unknown provider '{other}' — supported: ollama, ollama_cloud, openrouter, gemini, claude, kimi"),
             ));
         }
     };