fix: use Mistral free-tier models only (mistral-small-latest, nemo, 7b, 8x7b)

Switched from paid models (large-2411) to free-tier models.
Chat assistant also uses mistral-small-latest.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

packages/server/src/providers/mistral.ts

@@ -56,17 +56,16 @@ export class MistralProvider implements AIProvider {
   }
 }
 
-/** Primary Mistral models — best quality first (Pro plan) */
+/** Free-tier Mistral models — used first */
 export const MISTRAL_FREE_MODELS = [
-  'mistral-large-2411',      // Mistral Large — 123B, best quality ✅
-  'mistral-small-2503',      // Mistral Small latest — fast & accurate ✅
-  'mistral-saba-2502',       // Mistral Saba — strong reasoning ✅
-  'open-mistral-nemo',       // Nemo 12B — lightweight fallback ✅
+  'mistral-small-latest',    // Mistral Small — free tier, fast ✅
+  'open-mistral-nemo',       // Nemo 12B — free tier, lightweight ✅
+  'open-mistral-7b',         // Mistral 7B — free tier ✅
+  'open-mixtral-8x7b',       // Mixtral 8x7B MOE — free tier ✅
 ] as const;
 
-/** Additional Mistral models — used after primary are exhausted */
+/** Paid-tier Mistral models — fallback when free exhausted */
 export const MISTRAL_PAID_MODELS = [
-  'mistral-large-2407',      // Mistral Large v2 — solid backup ✅
-  'open-mixtral-8x22b',      // Mixtral 8x22B — large MOE model ✅
-  'pixtral-large-2411',      // Pixtral Large — multimodal capable ✅
+  'mistral-small-2503',      // Mistral Small latest ✅
+  'mistral-saba-2502',       // Mistral Saba — reasoning ✅
 ] as const;

packages/server/src/services/chatService.ts

@@ -70,7 +70,7 @@ async function parseIntent(userMessage: string): Promise<ParsedIntent> {
   const url = useMistral
     ? 'https://api.mistral.ai/v1/chat/completions'
     : 'https://api.groq.com/openai/v1/chat/completions';
-  const model = useMistral ? 'mistral-large-2411' : 'llama-3.3-70b-versatile';
+  const model = useMistral ? 'mistral-small-latest' : 'llama-3.3-70b-versatile';
 
   try {
     const response = await fetch(url, {