fix: Update context_window config to match 64K limit

CONSISTENCY FIX:

Updated MODEL_CONFIGS:
- context_window: 200000 → 64000 (matches max_tokens)
- Ensures UI displays correct limit
- Prevents confusion about capabilities

This aligns with commit 951b6b3 where max_tokens was limited to 64K.

🤖 Generated with Claude Code

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

app.py

@@ -21,7 +21,7 @@ MODEL_CONFIGS = {
         "model": "claude-sonnet-4-20250514",
         "api_key_env": "ANTHROPIC_API_KEY",
         "cost_per_1M_tokens": 3.00,
-        "context_window": 200000,
+        "context_window": 64000,
         "tier": "premium",
         "description": "Best for complex architecture"
     },
@@ -338,7 +338,7 @@ with gr.Blocks(
 
         **Pure prompt evaluation:** Describe your requirements in detail. The AI will decide language, framework, and architecture based on your instructions.
 
-        **Context Window:** 200,000 tokens output
+        **Context Window:** 64,000 tokens output
         """)
 
         with gr.Row():
@@ -386,7 +386,7 @@ with gr.Blocks(
 
         **Pure prompt evaluation:** Each model reads the same instructions and decides implementation details independently.
 
-        **Context Window:** 200,000 tokens output per model
+        **Context Window:** 64,000 tokens output per model
         """)
 
         with gr.Row():