feat: add configurable GitHub proxy settings (#401)

* docs: add GitHub proxy config design spec

* docs: add GitHub proxy config implementation plan

* feat(backend): use configurable github proxy for node upgrades

* feat(backend): use configurable github proxy for node install command

* feat(frontend): add github proxy config settings

* feat(script): support configurable github proxy in installer flows

Honor custom GitHub mirror settings across interactive and env-driven installer/update paths so script downloads match the panel configuration. Add shell regressions to lock down proxy prompting, URL recomputation, and non-interactive fallback behavior.

go-backend/internal/http/handler/mutations.go

@@ -453,7 +453,16 @@ func (h *Handler) nodeInstall(w http.ResponseWriter, r *http.Request) {
 		response.WriteJSON(w, response.Err(-2, err.Error()))
 		return
 	}
-	cmd := fmt.Sprintf("curl -L https://gcode.hostcentral.cc/https://github.com/Sagit-chu/flvx/releases/download/%s/install.sh -o ./install.sh && chmod +x ./install.sh && VERSION=%s ./install.sh -a %s -s %s", version, version, processServerAddress(panelAddr), secret)
+	enabled, proxyURL := h.getGithubProxyConfig()
+
+	var cmd string
+	if enabled {
+		cmd = fmt.Sprintf("curl -L %s/https://github.com/%s/releases/download/%s/install.sh -o ./install.sh && chmod +x ./install.sh && PROXY_ENABLED=true PROXY_URL=%s VERSION=%s ./install.sh -a %s -s %s",
+			proxyURL, githubRepo, version, proxyURL, version, processServerAddress(panelAddr), secret)
+	} else {
+		cmd = fmt.Sprintf("curl -L https://github.com/%s/releases/download/%s/install.sh -o ./install.sh && chmod +x ./install.sh && PROXY_ENABLED=false VERSION=%s ./install.sh -a %s -s %s",
+			githubRepo, version, version, processServerAddress(panelAddr), secret)
+	}
 	response.WriteJSON(w, response.OK(cmd))
 }
 

go-backend/internal/http/handler/upgrade.go

@@ -15,7 +15,6 @@ import (
 
 const (
 	githubRepo     = "Sagit-chu/flvx"
-	githubProxy    = "https://gcode.hostcentral.cc"
 	githubAPIBase  = "https://api.github.com"
 	githubHTMLBase = "https://github.com"
 	upgradeTimeout = 5 * time.Minute
@@ -23,6 +22,9 @@ const (
 
 	releaseChannelStable = "stable"
 	releaseChannelDev    = "dev"
+
+	defaultGithubProxyEnabled = true
+	defaultGithubProxyURL     = "https://gcode.hostcentral.cc"
 )
 
 var (
@@ -70,6 +72,39 @@ func releaseChannelLabel(channel string) string {
 	return "正式版"
 }
 
+func (h *Handler) getGithubProxyConfig() (enabled bool, proxyURL string) {
+	enabled = defaultGithubProxyEnabled
+	proxyURL = defaultGithubProxyURL
+
+	if h == nil || h.repo == nil {
+		return
+	}
+
+	if enabledCfg, err := h.repo.GetConfigByName("github_proxy_enabled"); err == nil && enabledCfg != nil {
+		enabled = enabledCfg.Value != "false"
+	}
+
+	if urlCfg, err := h.repo.GetConfigByName("github_proxy_url"); err == nil && urlCfg != nil && urlCfg.Value != "" {
+		proxyURL = strings.TrimSpace(urlCfg.Value)
+		if !strings.HasPrefix(proxyURL, "http://") && !strings.HasPrefix(proxyURL, "https://") {
+			proxyURL = "https://" + proxyURL
+		}
+		proxyURL = strings.TrimSuffix(proxyURL, "/")
+	}
+
+	return
+}
+
+func (h *Handler) buildGithubDownloadURL(version, filename string) string {
+	enabled, proxyURL := h.getGithubProxyConfig()
+	base := fmt.Sprintf("%s/%s/releases/download/%s/%s", githubHTMLBase, githubRepo, version, filename)
+
+	if enabled {
+		return fmt.Sprintf("%s/%s", proxyURL, base)
+	}
+	return base
+}
+
 func fetchGitHubReleases(perPage int) ([]githubRelease, error) {
 	if perPage <= 0 {
 		perPage = 20
@@ -149,14 +184,8 @@ func (h *Handler) nodeUpgrade(w http.ResponseWriter, r *http.Request) {
 		}
 	}
 
-	downloadURL := fmt.Sprintf(
-		githubProxy+"/%s/%s/releases/download/%s/gost-{ARCH}",
-		githubHTMLBase, githubRepo, version,
-	)
-	checksumURL := fmt.Sprintf(
-		githubProxy+"/%s/%s/releases/download/%s/gost-{ARCH}.sha256",
-		githubHTMLBase, githubRepo, version,
-	)
+	downloadURL := h.buildGithubDownloadURL(version, "gost-{ARCH}")
+	checksumURL := h.buildGithubDownloadURL(version, "gost-{ARCH}.sha256")
 
 	result, err := h.wsServer.SendCommand(req.ID, "UpgradeAgent", map[string]interface{}{
 		"downloadUrl": downloadURL,
@@ -213,14 +242,8 @@ func (h *Handler) nodeBatchUpgrade(w http.ResponseWriter, r *http.Request) {
 		}
 	}
 
-	downloadURL := fmt.Sprintf(
-		githubProxy+"/%s/%s/releases/download/%s/gost-{ARCH}",
-		githubHTMLBase, githubRepo, version,
-	)
-	checksumURL := fmt.Sprintf(
-		githubProxy+"/%s/%s/releases/download/%s/gost-{ARCH}.sha256",
-		githubHTMLBase, githubRepo, version,
-	)
+	downloadURL := h.buildGithubDownloadURL(version, "gost-{ARCH}")
+	checksumURL := h.buildGithubDownloadURL(version, "gost-{ARCH}.sha256")
 
 	type upgradeResult struct {
 		ID      int64  `json:"id"`