feat: improve proxy account setup and backup portability

tests/proxy-account-errors.test.ts

@@ -0,0 +1,48 @@
+import { describe, expect, it } from "vitest";
+import { createProxyOnlyAccountError, resolveProxyOnlyAccountErrorCode } from "../src/main/proxy-account-errors";
+
+const enabledSettings = { proxyDownloadEnabled: true, proxyListPath: "C:\\proxy.txt" };
+
+describe("Proxy-only account errors", () => {
+  it("distinguishes missing, unreadable, empty and unavailable fixed proxy settings", () => {
+    expect(resolveProxyOnlyAccountErrorCode(
+      { proxyDownloadEnabled: true, proxyListPath: "" },
+      { status: "blocked", reason: "proxy_file_unavailable" }
+    )).toBe("proxy_list_missing");
+    expect(resolveProxyOnlyAccountErrorCode(
+      enabledSettings,
+      { status: "blocked", reason: "proxy_file_unavailable" }
+    )).toBe("proxy_list_unreadable");
+    expect(resolveProxyOnlyAccountErrorCode(
+      enabledSettings,
+      { status: "blocked", reason: "no_valid_proxies" }
+    )).toBe("proxy_list_empty");
+    expect(resolveProxyOnlyAccountErrorCode(
+      enabledSettings,
+      { status: "blocked", reason: "proxy_index_unavailable" }
+    )).toBe("proxy_index_unavailable");
+  });
+
+  it("maps only transport failures from an active fixed proxy", () => {
+    const active = { status: "active", selectedIndex: 1, proxyCount: 20 } as const;
+    expect(resolveProxyOnlyAccountErrorCode(enabledSettings, active, "Prüfung fehlgeschlagen: fetch failed"))
+      .toBe("proxy_unreachable");
+    expect(resolveProxyOnlyAccountErrorCode(enabledSettings, active, "Prüfung fehlgeschlagen: The operation was aborted due to timeout"))
+      .toBe("proxy_unreachable");
+    expect(resolveProxyOnlyAccountErrorCode(enabledSettings, active, "Prüfung fehlgeschlagen (HTTP 407)"))
+      .toBe("proxy_unreachable");
+    expect(resolveProxyOnlyAccountErrorCode(enabledSettings, active, "Prüfung fehlgeschlagen (HTTP 503)"))
+      .toBeNull();
+    expect(resolveProxyOnlyAccountErrorCode(enabledSettings, active, "Ungültiger API-Token"))
+      .toBeNull();
+  });
+
+  it("does not classify errors while Proxy-only is disabled", () => {
+    expect(resolveProxyOnlyAccountErrorCode(
+      { proxyDownloadEnabled: false, proxyListPath: "" },
+      { status: "disabled" },
+      "fetch failed"
+    )).toBeNull();
+    expect(createProxyOnlyAccountError("proxy_list_missing").message).toBe("proxy_only_account:proxy_list_missing");
+  });
+});