feat(hosts): add drag-and-drop and global subscription ordering (#6895)

Hosts already had one saved order on the Hosts page, but subscriptions honoured
it only inside each inbound, so a host of a later inbound could never come before
one of an earlier inbound (#6894). A new opt-in setting makes raw/base64,
Clash/Mihomo and JSON subscriptions follow the Hosts page order across inbounds;
the default keeps today's inbound-first output unchanged. The Hosts table gains
drag-and-drop reordering next to the Up/Down buttons, on a pointer-reorder hook
the Routing Rules table now shares.

internal/sub/clash_service.go

@@ -56,6 +56,7 @@ func (s *SubClashService) getClash(subId string, host string, legacy bool) (stri
 	}
 
 	var proxies []map[string]any
+	var ordered []orderedSubEntry[func() []map[string]any]
 	var hasInactiveExternal bool
 	var hasEnabledClient bool
 
@@ -72,15 +73,29 @@ func (s *SubClashService) getClash(subId string, host string, legacy bool) (stri
 			continue
 		}
 		subReq.projectThroughFallbackMaster(inbound)
-		if hostEps := subReq.hostEndpoints(inbound, "clash"); len(hostEps) > 0 {
-			injectExternalProxy(inbound, hostEps)
+		if !subReq.hostsFirst {
+			if hostEps := subReq.hostEndpoints(inbound, "clash"); len(hostEps) > 0 {
+				injectExternalProxy(inbound, hostEps)
+			}
 		}
 		for _, client := range clients {
 			if client.Enable {
 				hasEnabledClient = true
 			}
 			seenEmails[client.Email] = struct{}{}
-			proxies = append(proxies, s.getProxies(subReq, inbound, client, host)...)
+			if subReq.hostsFirst {
+				for _, variant := range subReq.subscriptionHostVariants(inbound, "clash") {
+					render := func() []map[string]any { return s.getProxies(subReq, variant.inbound(subReq, inbound), client, host) }
+					ordered = append(ordered, orderedSubEntry[func() []map[string]any]{variant.order, render})
+				}
+			} else {
+				proxies = append(proxies, s.getProxies(subReq, inbound, client, host)...)
+			}
+		}
+	}
+	if subReq.hostsFirst {
+		for _, render := range orderedSubValues(ordered) {
+			proxies = append(proxies, render()...)
 		}
 	}
 	for _, ext := range externalLinks {