fix(accounting): wire up download button, fix LEFT JOIN in download DSPY

wwwroot/billing.ui

@@ -61,9 +61,17 @@
 					"widgettype": "Button",
 					"id": "billing_download_btn",
 					"options": {
-						"text": "下载Excel",
-						"css": "display: none; background-color: #52c41a; color: white; padding: 5px 15px; border-radius: 4px; cursor: pointer;"
-					}
+						"label": "下载Excel",
+						"css": "background-color: #52c41a; color: white; padding: 5px 15px; border-radius: 4px; cursor: pointer;"
+					},
+					"binds": [
+						{
+							"wid": "self",
+							"event": "click",
+							"actiontype": "script",
+							"script": "var f=bricks.getWidgetById('billing_form');if(!f)return;var v=f.values||{};if(!v.start_date||!v.end_date){bricks.show_error({title:'提示',message:'请先选择日期范围'});return;}var u='{{download_url}}?start_date='+encodeURIComponent(v.start_date)+'&end_date='+encodeURIComponent(v.end_date);fetch(u,{credentials:'include'}).then(function(r){return r.json()}).then(function(d){if(d.status!=='ok'){bricks.show_error({title:'下载失败',message:d.data.message});return;}var b=atob(d.data.content),n=b.length,arr=new Uint8Array(n);for(var i=0;i<n;i++)arr[i]=b.charCodeAt(i);var blob=new Blob([arr],{type:'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet'});var a=document.createElement('a');a.href=URL.createObjectURL(blob);a.download=d.data.filename;a.click()}).catch(function(e){bricks.show_error({title:'下载失败',message:e.toString()})})"
+						}
+					]
 				}
 			]
 		},

wwwroot/billing_download.dspy

@@ -23,7 +23,7 @@ async with get_sor_context(request._run_ns, 'accounting') as sor:
 d.summary, d.amount, d.balance
 from acc_detail d
 join account a on d.accountid = a.id COLLATE utf8mb4_unicode_ci
-join subject s on a.subjectid = s.id COLLATE utf8mb4_unicode_ci
+left join subject s on a.subjectid = s.id COLLATE utf8mb4_unicode_ci
 where a.orgid = ${orgid}$
 	and d.acc_date >= ${start_date}$
 	and d.acc_date <= ${end_date}$