Remove Qwen2.5 3B - keep only 1.5B as extraction model

Qwen2.5 3B showed poor performance:
- Misclassified action_items as key_points (0 action items extracted)
- 14.3% duplicate rate
- Slower (116s vs 80s)
- No quality improvement over 1.5B

Qwen2.5 1.5B is the optimal choice:
- Perfect categorization
- Zero duplicates
- Faster processing
- Proven 100% extraction success

app.py

@@ -689,22 +689,6 @@ EXTRACTION_MODELS = {
             "repeat_penalty": 1.0,
         },
     },
-    "qwen2.5_3b": {
-        "name": "Qwen2.5 3B (128K Context)",
-        "repo_id": "Qwen/Qwen2.5-3B-Instruct-GGUF",
-        "filename": "*q4_k_m.gguf",
-        "max_context": 131072,
-        "default_n_ctx": 4096,
-        "params_size": "3B",
-        "supports_reasoning": False,
-        "supports_toggle": False,
-        "inference_settings": {
-            "temperature": 0.2,
-            "top_p": 0.9,
-            "top_k": 30,
-            "repeat_penalty": 1.0,
-        },
-    },
 }
 
 DEFAULT_EXTRACTION_MODEL = "qwen2.5_1.5b"