feat: refine account management and targeted editing

Add local provider icons, larger compact account rows, the requested column order, and full username display while keeping secrets masked. Replace provider-wide editing with a row-specific editor that preserves sibling accounts, exact limits, live usage counters, and status metadata. Add targeted credential validation, release notices, and regression coverage.

tests/account-status-persistence.test.ts

@@ -0,0 +1,28 @@
+import { describe, expect, it } from "vitest";
+import { canPersistExpectedAccountStatus } from "../src/main/account-status-persistence";
+import type { DebridAccountStatus } from "../src/shared/types";
+
+function status(accountId: string, valid = true): DebridAccountStatus {
+  return {
+    accountId,
+    provider: "megadebrid",
+    label: "Account 1",
+    maskedLogin: "us***om",
+    valid,
+    isPremium: true,
+    premiumUntilMs: null,
+    message: valid ? "OK" : "Ungültig",
+    checkedAt: 1
+  };
+}
+
+describe("account status persistence", () => {
+  it("accepts only one valid status for the expected account", () => {
+    expect(canPersistExpectedAccountStatus([status("expected")], "expected")).toBe(true);
+    expect(canPersistExpectedAccountStatus([], "expected")).toBe(false);
+    expect(canPersistExpectedAccountStatus([status("other")], "expected")).toBe(false);
+    expect(canPersistExpectedAccountStatus([status("expected", false)], "expected")).toBe(false);
+    expect(canPersistExpectedAccountStatus([status("expected"), status("other")], "expected")).toBe(false);
+    expect(canPersistExpectedAccountStatus([status("expected")], "")).toBe(false);
+  });
+});