proxy: extend /running endpoint with additional process data (#474)

Extend the /running endpoint to return more details about running
processes beyond just model and state.

- add cmd field to show the command being executed
- add proxy field to show the proxy URL
- add ttl (UnloadAfter) for automatic unloading configuration
- add name and description for model metadata
- update tests to verify new fields are returned correctly

fixes #471

proxy/proxymanager.go

@@ -930,6 +930,11 @@ func (pm *ProxyManager) listRunningProcessesHandler(context *gin.Context) {
 				runningProcesses = append(runningProcesses, gin.H{
 					"model":       process.ID,
 					"state":       process.state,
+					"cmd":         process.config.Cmd,
+					"proxy":       process.config.Proxy,
+					"ttl":         process.config.UnloadAfter,
+					"name":        process.config.Name,
+					"description": process.config.Description,
 				})
 			}
 		}

proxy/proxymanager_test.go

@@ -674,6 +674,11 @@ func TestProxyManager_RunningEndpoint(t *testing.T) {
 		Running []struct {
 			Model       string `json:"model"`
 			State       string `json:"state"`
+			Cmd         string `json:"cmd"`
+			Proxy       string `json:"proxy"`
+			TTL         int    `json:"ttl"`
+			Name        string `json:"name"`
+			Description string `json:"description"`
 		} `json:"running"`
 	}
 
@@ -721,6 +726,11 @@ func TestProxyManager_RunningEndpoint(t *testing.T) {
 
 		// Is the model loaded?
 		assert.Equal(t, "ready", response.Running[0].State)
+
+		// Verify extended fields are present
+		assert.NotEmpty(t, response.Running[0].Cmd, "cmd should be populated")
+		assert.NotEmpty(t, response.Running[0].Proxy, "proxy should be populated")
+		assert.Equal(t, 0, response.Running[0].TTL, "ttl should default to 0")
 	})
 }