chore(models): update model tiers to premium and adjust availability in constants

backend/utils/constants.py

@@ -8,7 +8,7 @@ MODELS = {
             "input_cost_per_million_tokens": 3.00,
             "output_cost_per_million_tokens": 15.00
         },
-        "tier_availability": ["free", "paid"]
+        "tier_availability": ["paid"]
     },
     # "openrouter/deepseek/deepseek-chat": {
     #     "aliases": ["deepseek"],
@@ -56,7 +56,7 @@ MODELS = {
             "input_cost_per_million_tokens": 5.00,
             "output_cost_per_million_tokens": 15.00
         },
-        "tier_availability": ["free", "paid"]
+        "tier_availability": ["paid"]
     },
     
     # Paid tier only models

frontend/src/components/thread/chat-input/_use-model-selection.ts

@@ -32,7 +32,7 @@ export interface CustomModel {
 export const MODELS = {
   // Free tier models (available to all users)
   'claude-sonnet-4': { 
-    tier: 'free',
+    tier: 'premium',
     priority: 100, 
     recommended: true,
     lowQuality: false
@@ -59,7 +59,7 @@ export const MODELS = {
     lowQuality: false
   },
   'grok-4': { 
-    tier: 'free', 
+    tier: 'premium', 
     priority: 98,
     recommended: false,
     lowQuality: false

frontend/src/components/thread/chat-input/model-selector.tsx

@@ -599,8 +599,8 @@ export const ModelSelector: React.FC<ModelSelectorProps> = ({
                 {/* Premium Models Section */}
                 <div className="mt-4 border-t border-border pt-2">
                   <div className="px-3 py-1.5 text-xs font-medium text-blue-500 flex items-center">
-                    {/* <Crown className="h-3.5 w-3.5 mr-1.5" /> */}
-                    Additional Models
+                    <Crown className="h-3.5 w-3.5 mr-1.5" />
+                    Premium Models
                   </div>
 
                   {/* Premium models container with paywall overlay */}