feat(pricing): refresh catalog pricing snapshot

Add the free minimax/minimax-m3-free and minimax/minimax-m2.7-free
promotional variants (free through September 5, 2026) and
tencent/hy4-preview, drop the retired stealth/ox-alpha, and refresh the
model-id and pricing snapshots to the current 62-model catalog verified
on 2026-08-28.

tests/fixtures/commandcode-model-ids.json

@@ -1,5 +1,5 @@
 {
-  "fetchedAt": "2026-08-25T13:32:11.631Z",
+  "fetchedAt": "2026-08-28T09:27:52.554Z",
   "source": "https://api.commandcode.ai/provider/v1/models",
   "modelIds": [
     "claude-sonnet-5",
@@ -32,6 +32,8 @@
     "zai-org/GLM-5",
     "MiniMaxAI/MiniMax-M3",
     "MiniMaxAI/MiniMax-M2.7",
+    "minimax/minimax-m3-free",
+    "minimax/minimax-m2.7-free",
     "MiniMaxAI/MiniMax-M2.5",
     "xiaomi/mimo-v2.5-pro",
     "xiaomi/mimo-v2.5",
@@ -46,6 +48,7 @@
     "stepfun/Step-3.7-Flash",
     "stepfun/Step-3.5-Flash",
     "tencent/hy3-paid",
+    "tencent/hy4-preview",
     "google/gemini-3.7-flash",
     "google/gemini-3.6-flash",
     "google/gemini-3.5-flash",
@@ -55,7 +58,6 @@
     "nvidia/nemotron-3-ultra-550b-a55b",
     "thinkingmachines/inkling",
     "thinkingmachines/inkling-small",
-    "stealth/ox-alpha",
     "poolside/laguna-s-2.1-free",
     "meta/muse-spark-1.1",
     "meta/muse-spark-1.2",