Fix Qwen2.5 3B filename pattern to lowercase

- Changed from *Q4_K_M.gguf to *q4_k_m.gguf
- File in repo is qwen2.5-3b-instruct-q4_k_m.gguf (lowercase)
- Matches actual filename in Qwen/Qwen2.5-3B-Instruct-GGUF

app.py

@@ -692,7 +692,7 @@ EXTRACTION_MODELS = {
     "qwen2.5_3b": {
         "name": "Qwen2.5 3B (128K Context)",
         "repo_id": "Qwen/Qwen2.5-3B-Instruct-GGUF",
-        "filename": "*Q4_K_M.gguf",
+        "filename": "*q4_k_m.gguf",
         "max_context": 131072,
         "default_n_ctx": 4096,
         "params_size": "3B",