feat(chat): Dwa klucze API - Free tier dla Flash, Paid dla Pro

- GOOGLE_GEMINI_API_KEY_FREE: klucz Free tier dla Flash (darmowy)
- GOOGLE_GEMINI_API_KEY: klucz Paid tier dla Pro (płatny)
- GeminiService automatycznie wybiera klucz na podstawie modelu
- Flash pricing ustawiony na $0.00 (Free tier)
- UI pokazuje Flash jako "Darmowy"

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

app.py

@@ -4623,6 +4623,52 @@ def chat_send_message(conversation_id):
         # Get model from request or session (flash = default, pro = premium)
         model_choice = data.get('model') or session.get('chat_model', 'flash')
 
+        # Check Pro model limits (Flash is free - no limits)
+        if model_choice == 'pro':
+            # Users without limits (admins)
+            UNLIMITED_USERS = ['maciej.pienczyn@inpi.pl', 'artur.wiertel@waterm.pl']
+
+            if current_user.email not in UNLIMITED_USERS:
+                # Check daily and monthly limits for Pro
+                from database import AIApiCost
+                db_check = SessionLocal()
+                try:
+                    # Daily limit: $2.00
+                    today_start = datetime.now().replace(hour=0, minute=0, second=0, microsecond=0)
+                    daily_costs = db_check.query(AIApiCost).filter(
+                        AIApiCost.user_id == current_user.id,
+                        AIApiCost.timestamp >= today_start,
+                        AIApiCost.model_name.like('%pro%')
+                    ).all()
+                    daily_total = sum(c.total_cost_usd or 0 for c in daily_costs)
+
+                    if daily_total >= 2.0:
+                        return jsonify({
+                            'success': False,
+                            'error': 'Osiągnięto dzienny limit Pro ($2.00). Spróbuj jutro lub użyj darmowego modelu Flash.',
+                            'limit_exceeded': 'daily',
+                            'daily_used': round(daily_total, 2)
+                        }), 429
+
+                    # Monthly limit: $20.00
+                    month_start = datetime.now().replace(day=1, hour=0, minute=0, second=0, microsecond=0)
+                    monthly_costs = db_check.query(AIApiCost).filter(
+                        AIApiCost.user_id == current_user.id,
+                        AIApiCost.timestamp >= month_start,
+                        AIApiCost.model_name.like('%pro%')
+                    ).all()
+                    monthly_total = sum(c.total_cost_usd or 0 for c in monthly_costs)
+
+                    if monthly_total >= 20.0:
+                        return jsonify({
+                            'success': False,
+                            'error': 'Osiągnięto miesięczny limit Pro ($20.00). Użyj darmowego modelu Flash.',
+                            'limit_exceeded': 'monthly',
+                            'monthly_used': round(monthly_total, 2)
+                        }), 429
+                finally:
+                    db_check.close()
+
         # Map model choice to actual model name
         model_map = {
             'flash': '3-flash',

gemini_service.py

@@ -58,13 +58,14 @@ THINKING_LEVELS = {
 }
 
 # Pricing per 1M tokens (USD) - updated 2026-01-29
+# Note: Flash on Free Tier = $0.00, Pro on Paid Tier = paid pricing
 GEMINI_PRICING = {
     'gemini-2.5-flash': {'input': 0.30, 'output': 2.50, 'thinking': 0},
     'gemini-2.5-flash-lite': {'input': 0.10, 'output': 0.40, 'thinking': 0},
     'gemini-2.5-pro': {'input': 1.25, 'output': 10.00, 'thinking': 0},
     'gemini-2.0-flash': {'input': 0.10, 'output': 0.40, 'thinking': 0},
-    'gemini-3-flash-preview': {'input': 0.50, 'output': 3.00, 'thinking': 1.00},
+    'gemini-3-flash-preview': {'input': 0.00, 'output': 0.00, 'thinking': 0.00},  # Free tier!
-    'gemini-3-pro-preview': {'input': 2.00, 'output': 12.00, 'thinking': 4.00},
+    'gemini-3-pro-preview': {'input': 2.00, 'output': 12.00, 'thinking': 4.00},   # Paid tier
 }
 
 
@@ -82,12 +83,24 @@ class GeminiService:
         Initialize Gemini service.
 
         Args:
-            api_key: Google AI API key (reads from GOOGLE_GEMINI_API_KEY env if not provided)
+            api_key: Google AI API key (reads from env if not provided)
             model: Model to use ('flash', 'flash-lite', 'pro', '3-flash', '3-pro')
             thinking_level: Reasoning depth ('minimal', 'low', 'medium', 'high')
             include_thoughts: Whether to include thinking process in response (for debugging)
+
+        API Keys (auto-selected by model):
+            - GOOGLE_GEMINI_API_KEY_FREE: Free tier for Flash models (no cost)
+            - GOOGLE_GEMINI_API_KEY: Paid tier for Pro models
         """
-        self.api_key = api_key or os.getenv('GOOGLE_GEMINI_API_KEY')
+        # Auto-select API key based on model (Free tier for Flash, Paid for Pro)
+        if api_key:
+            self.api_key = api_key
+        elif model in ('3-pro', 'pro'):
+            # Pro models use paid tier
+            self.api_key = os.getenv('GOOGLE_GEMINI_API_KEY')
+        else:
+            # Flash models prefer free tier, fallback to paid
+            self.api_key = os.getenv('GOOGLE_GEMINI_API_KEY_FREE') or os.getenv('GOOGLE_GEMINI_API_KEY')
 
         # Debug: Log API key (masked)
         if self.api_key:

templates/chat.html

@@ -733,6 +733,16 @@
         background: linear-gradient(135deg, #f59e0b 0%, #d97706 100%);
     }
 
+    .thinking-option-badge.free {
+        background: linear-gradient(135deg, #10b981 0%, #059669 100%);
+    }
+
+    .thinking-option-price.free {
+        color: #10b981;
+        font-weight: 500;
+        font-style: normal;
+    }
+
     .thinking-option-price {
         display: block;
         font-size: 11px;
@@ -1247,10 +1257,10 @@
                             <div class="thinking-option-header">
                                 <span class="thinking-option-icon">⚡</span>
                                 <span class="thinking-option-name">Gemini Flash</span>
-                                <span class="thinking-option-badge">Domyślny</span>
+                                <span class="thinking-option-badge free">Darmowy</span>
                             </div>
-                            <p class="thinking-option-desc">Szybki i ekonomiczny. Dla prostych pytań o firmy, kontakty, wydarzenia.</p>
+                            <p class="thinking-option-desc">Szybki i skuteczny. Dla większości pytań o firmy, kontakty, wydarzenia.</p>
-                            <span class="thinking-option-price">~$0.05/pytanie</span>
+                            <span class="thinking-option-price free">Bez opłat</span>
                         </div>
                         <div class="thinking-option" data-model="pro" onclick="setModel('pro')">
                             <div class="thinking-option-header">
@@ -1258,8 +1268,8 @@
                                 <span class="thinking-option-name">Gemini Pro</span>
                                 <span class="thinking-option-badge premium">Premium</span>
                             </div>
-                            <p class="thinking-option-desc">Głęboka analiza. Dla złożonych pytań, strategii, rekomendacji.</p>
+                            <p class="thinking-option-desc">Głęboka analiza i rozumowanie. Dla złożonych pytań, strategii, rekomendacji.</p>
-                            <span class="thinking-option-price">~$0.20/pytanie</span>
+                            <span class="thinking-option-price">~$0.20/pytanie · limit: $2/dzień</span>
                         </div>
                     </div>
                 </div>