Fix GPT-5 API compatibility and add AIUsageLog migration

- Add AIUsageLog table migration for token tracking
- Fix GPT-5 temperature parameter (not supported, like o-series)
- Add usesNewTokenParam() and supportsTemperature() functions
- Add GPT-5+ category to model selection UI
- Update model sorting to show GPT-5+ first

GPT-5 and newer models use max_completion_tokens and don't support
custom temperature values, similar to reasoning models.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/server/routers/settings.ts

@@ -9,6 +9,8 @@ import { getAIUsageStats, getCurrentMonthCost, formatCost } from '@/server/utils
  */
 function categorizeModel(modelId: string): string {
   const id = modelId.toLowerCase()
+  // GPT-5+ series (newest models)
+  if (id.startsWith('gpt-5') || id.startsWith('gpt-6') || id.startsWith('gpt-7')) return 'gpt-5+'
   if (id.startsWith('gpt-4o')) return 'gpt-4o'
   if (id.startsWith('gpt-4')) return 'gpt-4'
   if (id.startsWith('gpt-3.5')) return 'gpt-3.5'
@@ -220,11 +222,11 @@ export const settingsRouter = router({
       category: categorizeModel(model),
     }))
 
-    // Sort: GPT-4o first, then other GPT-4, then GPT-3.5, then reasoning models
+    // Sort: GPT-5+ first, then GPT-4o, then other GPT-4, then GPT-3.5, then reasoning models
     const sorted = categorizedModels.sort((a, b) => {
-      const order = ['gpt-4o', 'gpt-4', 'gpt-3.5', 'reasoning']
-      const aOrder = order.findIndex(cat => a.category.startsWith(cat))
-      const bOrder = order.findIndex(cat => b.category.startsWith(cat))
+      const order = ['gpt-5+', 'gpt-4o', 'gpt-4', 'gpt-3.5', 'reasoning', 'other']
+      const aOrder = order.findIndex(cat => a.category === cat)
+      const bOrder = order.findIndex(cat => b.category === cat)
       if (aOrder !== bOrder) return aOrder - bOrder
       return a.id.localeCompare(b.id)
     })