fix(litellm): route kimi-k3 to the Kimi Code (coding) endpoint

The Heid panel plan uses Kimi's coding endpoint, not the general Moonshot API.
kimi-k3 now → openai/k3 @ https://api.kimi.com/coding/v1 (KIMI_CODE_API_KEY,
Vivace); the original general-endpoint entry is kept as kimi-k3-gen-api
(api.moonshot.ai, MOONSHOT_API_KEY). Both verified live through the gateway.
Same k3 constraints on both: temperature MUST be 1 (else 400), reasoning model
(reasoning_content vs content, needs adequate max_tokens).

stacks/litellm/.env.example

@@ -35,7 +35,12 @@ VLLM_API_KEY=
 # (glm-5.1 / glm-5-turbo / glm-4.7 / glm-4.5-air).
 Z_AI_API_KEY=
 
-# Moonshot AI (Kimi) key — fronts kimi-k3 (https://api.moonshot.ai/v1). PAID.
+# Kimi (Moonshot) keys — PAID.
+#   KIMI_CODE_API_KEY — the CODING endpoint (https://api.kimi.com/coding/v1),
+#     Vivace membership; fronts the primary `kimi-k3` arm (upstream model `k3`).
+#   MOONSHOT_API_KEY  — the general endpoint (https://api.moonshot.ai/v1);
+#     fronts the `kimi-k3-gen-api` variant.
+KIMI_CODE_API_KEY=
 MOONSHOT_API_KEY=
 
 # --- Langfuse-ready (leave blank for the lean first cut) ---

stacks/litellm/compose.yaml

@@ -50,6 +50,10 @@ services:
       # Moonshot Kimi, etc.). Paid — only gateway-keyed callers reach them,
       # but they spend.
       - Z_AI_API_KEY=${Z_AI_API_KEY:-}
+      # Kimi: KIMI_CODE_API_KEY = the coding endpoint (api.kimi.com/coding, the
+      # primary kimi-k3 arm); MOONSHOT_API_KEY = the general api.moonshot.ai
+      # endpoint (the kimi-k3-gen-api variant).
+      - KIMI_CODE_API_KEY=${KIMI_CODE_API_KEY:-}
       - MOONSHOT_API_KEY=${MOONSHOT_API_KEY:-}
       # Langfuse-ready: blank until you bolt Langfuse on. Filling these +
       # uncommenting the callback in config.yaml is the entire upgrade.

stacks/litellm/conf/config.yaml

@@ -362,22 +362,34 @@ model_list:
       temperature: 0.6
       top_p: 0.95
 
-  # --- Kimi K3 (Moonshot AI, cloud API) — paid passthrough fronted for unified
-  #     logging alongside the local + z.ai inference. OpenAI-compatible endpoint
-  #     (https://api.moonshot.ai/v1) → openai/ provider. Flagship long-horizon
-  #     coding + knowledge model, 1M-token context (platform.kimi.ai docs). Model
-  #     id `kimi-k3` confirmed live via /v1/models 2026-07-25 (siblings kimi-k2.6,
-  #     kimi-k2.7-code, kimi-k2.7-code-highspeed — add explicit entries if wanted).
-  #     PAID — spends Moonshot credits; reachable by any gateway key scoped to it
-  #     (the shared all-agents key spans all proxy models). Key in .env
-  #     (MOONSHOT_API_KEY). CONSTRAINT (Moonshot, verified live 2026-07-25): K3
-  #     ONLY accepts temperature=1 — any other value 400s ("only 1 is allowed for
-  #     this model"). So temperature is pinned to 1 here as the default; callers
-  #     must NOT override it with another value. K3 is also a REASONING model:
-  #     the CoT comes back in `reasoning_content`, the answer in `content` — give
-  #     it adequate max_tokens or content returns EMPTY (reasoning eats a tiny
-  #     budget). Verified live through the gateway 2026-07-25 (17+25→"42"). ---
+  # --- Kimi K3 — CODING endpoint (Kimi Code / Vivace membership). THE PRIMARY
+  #     Kimi arm the Heid cross-frontier panel plan uses. OpenAI-compatible base
+  #     https://api.kimi.com/coding/v1 → openai/ provider, upstream model id `k3`
+  #     (1M-context; the coding lineup also carries k3-256k, kimi-for-coding,
+  #     kimi-for-coding-highspeed — ids confirmed live via /models 2026-07-25).
+  #     PAID (Vivace subscription); key KIMI_CODE_API_KEY in .env. CONSTRAINT
+  #     (verified live 2026-07-25): k3 accepts ONLY temperature=1 — any other value
+  #     400s ("only 1 is allowed for this model") — so it is pinned here; callers
+  #     must NOT override it. k3 is also a REASONING model (thinking-effort tiers
+  #     low/high/max per Kimi Code docs): CoT returns in `reasoning_content`, the
+  #     answer in `content` — give it adequate max_tokens or content returns EMPTY
+  #     (reasoning eats a tiny budget). ---
   - model_name: kimi-k3
+    litellm_params:
+      model: openai/k3
+      api_base: https://api.kimi.com/coding/v1
+      api_key: os.environ/KIMI_CODE_API_KEY
+      temperature: 1
+    model_info:
+      mode: chat
+
+  # --- Kimi K3 — GENERAL Moonshot API endpoint (https://api.moonshot.ai/v1),
+  #     kept as the `-gen-api` variant. The plan uses the CODING endpoint above;
+  #     this is the general-platform route (originally wired then demoted when the
+  #     coding endpoint became canonical). OpenAI-compatible, upstream `kimi-k3`,
+  #     key MOONSHOT_API_KEY. Same temperature=1 + reasoning-model constraints as
+  #     the coding k3 (verified live through the gateway 2026-07-25, 17+25→"42"). ---
+  - model_name: kimi-k3-gen-api
     litellm_params:
       model: openai/kimi-k3
       api_base: https://api.moonshot.ai/v1