refactor(backend): reorganize top-level layout

- ssh/ renamed to hosts/ (it covers SSH, RDP, VNC, Telnet, Docker, metrics)
- serial/serial.ts and guacamole/ moved inside hosts/
- dashboard.ts and homepage.ts moved to services/
- swagger.ts moved to utils/ with adjusted scan globs

Import paths and the generate:openapi script updated; ports and endpoints
unchanged.

src/backend/hosts/jump-host-proxy.ts

@@ -0,0 +1,51 @@
+import type { ProxyNode } from "../../types/index.js";
+import type { SOCKS5Config } from "../utils/socks5-helper.js";
+
+type JumpHostProxyConfig = {
+  useSocks5?: boolean | null;
+  socks5Host?: string | null;
+  socks5Port?: number | null;
+  socks5Username?: string | null;
+  socks5Password?: string | null;
+  socks5ProxyChain?: ProxyNode[] | string | null;
+};
+
+function parseProxyChain(value: JumpHostProxyConfig["socks5ProxyChain"]) {
+  if (Array.isArray(value)) {
+    return value;
+  }
+
+  if (typeof value !== "string" || value.length === 0) {
+    return [];
+  }
+
+  try {
+    const parsed = JSON.parse(value);
+    return Array.isArray(parsed) ? (parsed as ProxyNode[]) : [];
+  } catch {
+    return [];
+  }
+}
+
+export function getJumpHostSocks5Config(
+  firstHop: JumpHostProxyConfig | null | undefined,
+  fallbackConfig?: SOCKS5Config | null,
+): SOCKS5Config | null {
+  if (!firstHop?.useSocks5) {
+    return fallbackConfig ?? null;
+  }
+
+  const socks5ProxyChain = parseProxyChain(firstHop.socks5ProxyChain);
+  if (!firstHop.socks5Host && socks5ProxyChain.length === 0) {
+    return fallbackConfig ?? null;
+  }
+
+  return {
+    useSocks5: true,
+    socks5Host: firstHop.socks5Host ?? undefined,
+    socks5Port: firstHop.socks5Port ?? undefined,
+    socks5Username: firstHop.socks5Username ?? undefined,
+    socks5Password: firstHop.socks5Password ?? undefined,
+    socks5ProxyChain,
+  };
+}