feat: upgrade primary model from llama3.1:8b to qwen2.5:14b (#140)

- Swap OLLAMA_MODEL_PRIMARY to qwen2.5:14b for better reasoning
- llama3.1:8b-instruct becomes fallback
- Update .env default and README quick start
- Fix hardcoded model assertions in tests

qwen2.5:14b provides significantly better multi-step reasoning
and tool calling reliability while still running locally on
modest hardware. The 8B model remains as automatic fallback.

Co-authored-by: Trip T <trip@local>

tests/dashboard/test_dashboard.py

@@ -86,7 +86,7 @@ def test_agents_list_metadata(client):
     response = client.get("/agents")
     agent = next(a for a in response.json()["agents"] if a["id"] == "default")
     assert agent["name"] == "Agent"
-    assert agent["model"] == "llama3.1:8b-instruct"
+    assert agent["model"] == "qwen2.5:14b"
     assert agent["type"] == "local"
 
 

tests/dashboard/test_mobile_scenarios.py

@@ -298,10 +298,10 @@ def test_M605_health_status_passes_model_to_template(client):
         return_value=True,
     ):
         response = client.get("/health/status")
-    # The default model is llama3.1:8b-instruct — it should appear from settings
+    # The default model is qwen2.5:14b — it should appear from settings
     assert response.status_code == 200
     assert (
-        "llama3.1" in response.text
+        "qwen2.5" in response.text
     )  # rendered via template variable, not hardcoded literal