fix: add model descriptor and brand entry for mistral-vibe-cli-latest

The catalog entry referenced a modelDescriptorId that had no matching
descriptor in src/integrations/models/mistral.ts, causing integration
test failures (gateway modelDescriptorId references have model metadata,
registry is valid after loading all descriptors).

Co-Authored-By: OpenClaude (mimo-v2.5-pro) <openclaude@gitlawb.com>

Author: currentsuspect

src/integrations/brands/mistral.ts

@@ -13,6 +13,7 @@ export default defineBrand({
     supportsPreciseTokenCount: false,
   },
   modelIds: [
+    'mistral-vibe-cli-latest',
     'mistral-large-latest',
     'mistral-small-latest',
     'devstral-latest',

src/integrations/models/mistral.ts

@@ -31,6 +31,7 @@ function mistralModel(
 export default [
   mistralModel('mistral-large-latest', 'Mistral Large Latest', 256_000, 32_768),
   mistralModel('mistral-small-latest', 'Mistral Small Latest', 256_000, 32_768),
+  mistralModel('mistral-vibe-cli-latest', 'Vibe CLI Latest', 262_144, 32_768),
   mistralModel('devstral-latest', 'Devstral Latest', 256_000, 32_768),
   mistralModel('ministral-3b-latest', 'Ministral 3B Latest', 256_000, 32_768),
   mistralModel('mixtral-8x7b-32768', 'Mixtral 8x7B 32768', 32_768, 32_768),