feat(proxmox): add journalctl streaming API endpoint for LXC containers

Add new /api/v1/proxmox/journalctl/:node/:vmid/:service endpoint that
streams real-time journalctl output from Proxmox LXC containers via
WebSocket connection. This enables live monitoring of container services
from the GoDoxy WebUI.

Implementation includes:
- New proxmox API handler with path parameter validation
- WebSocket upgrade for streaming output
- LXCCommand helper for executing commands over Proxmox VNC websocket
- LXCJournalctl wrapper for convenient journalctl -u service -f invocation
- Updated API documentation with proxmox integration

internal/api/handler.go

@@ -14,6 +14,7 @@ import (
 	fileApi "github.com/yusing/godoxy/internal/api/v1/file"
 	homepageApi "github.com/yusing/godoxy/internal/api/v1/homepage"
 	metricsApi "github.com/yusing/godoxy/internal/api/v1/metrics"
+	proxmoxApi "github.com/yusing/godoxy/internal/api/v1/proxmox"
 	routeApi "github.com/yusing/godoxy/internal/api/v1/route"
 	"github.com/yusing/godoxy/internal/auth"
 	"github.com/yusing/godoxy/internal/common"
@@ -138,6 +139,11 @@ func NewHandler(requireAuth bool) *gin.Engine {
 			docker.POST("/restart", dockerApi.Restart)
 			docker.GET("/stats/:id", dockerApi.Stats)
 		}
+
+		proxmox := v1.Group("/proxmox")
+		{
+			proxmox.GET("/journalctl/:node/:vmid/:service", proxmoxApi.Journalctl)
+		}
 	}
 
 	return r