feat(shortcut): support unassigned hotkeys

[yixinshark]

Summary

• Allow a shortcut to be left without any hotkey: it stays visible in the list (shown as "None") without being registered with the compositor, so ReplaceHotkey can intentionally unassign a binding and Reset can restore the default later.
• Reset: unregister reset targets up front and only mutate local state after the compositor confirms the commit; on commit failure leave the map and dconfig untouched so state stays consistent (matching the rollback contract of ModifyHotkeys/Disable).
• Reset: drop reset targets from the map so the async valueChanged restore takes the new-entry path and always emits ShortcutChanged, even when the restored default is unassigned.
• Add KeyConfig operator==/!= and skip onKeyConfigChanged work (and the spurious ShortcutChanged) when the incoming config is unchanged.

Test plan

• Assign a custom hotkey, then Reset: the shortcut returns to its default (or to unassigned when the default is empty) and the control center reflects the change.
• Reset a set where defaults would swap/collide: no async registration conflict; each restores correctly.
• Confirm an unchanged DConfig write no longer emits a redundant ShortcutChanged.

Pms: BUG-365989

[sourcery-ai]

Sorry @yixinshark, you have reached your weekly rate limit of 500000 diff characters.

Please try again later or upgrade to continue using Sourcery

[deepin-ci-robot]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by: yixinshark

The full list of commands accepted by this bot can be found here.

Details

Needs approval from an approver in each of these files:

• debian/deepin/OWNERS

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment

[deepin-ci-robot]

deepin pr auto review

★ 总体评分：95分

■ 【总体评价】

代码重构了快捷键重置与冲突处理逻辑，解决了空快捷键状态下的UI丢失与重置冲突问题
逻辑严密、注释充分且无任何安全漏洞，符合优秀标准

■ 【详细分析】

• 1.语法逻辑（完全正确）✓

重构后的 KeybindingManager::Reset() 采用“先收集注销->同步提交->清空本地缓存->触发DConfig重置”的严格顺序，彻底杜绝了异步重置过程中旧绑定未释放引发的快捷键冲突。KeyConfig::isValid() 放宽校验与 registerShortcut() 中对空 hotkeys 的提前返回逻辑完美配合，保证了空快捷键可见但不绑定的状态一致性。onKeyConfigChanged() 中引入的 operator== 判断有效避免了无状态变更时的冗余信号发射
建议：无

• 2.代码质量（良好）✓

将 ConfigLoader::resetConfig() 拆分为 resettableHotkeyIds() 和 resetHotkeys() 两个职责单一的函数，提升了可读性和可测试性。使用匿名命名空间管理 kDefaultShortcutAppId 等常量，符合 C++ 最佳实践。新增的 containsEmptyHotkey 采用 std::any_of 算法，代码简洁现代。注释详尽，准确解释了“为何需要先 commitSync 再重置 DConfig”等关键设计决策
建议：无

• 3.代码性能（高效）✓

containsEmptyHotkey 使用短路求值的 std::any_of，在遇到首个空串时立即返回，避免了不必要的全量遍历。Reset() 中虽然对目标列表进行了两次遍历（注销与清理），但由于中间存在 commitSync 的 IPC 阻塞调用，两次 O(N) 遍历的开销完全可忽略。operator== 逐字段比较对于轻量级结构体 KeyConfig 而言是最优解
建议：无

• 4.代码安全（存在0个安全漏洞）✓

漏洞对比统计：新增漏洞 0 个，减少漏洞 0 个，持平 0 个
代码未引入任何安全风险。ModifyHotkeys 和 ReplaceHotkey 入口处均增加了严格的空值拦截，防止非法空快捷键注入。resetHotkeys 通过 m_configs.value(id) 获取指针并做空指针保护，杜绝了悬空指针解引用。常量字符串统一使用 QString::fromLatin1 处理，避免了潜在的编码注入风险
建议：无

■ 【改进建议代码示例】

// 当前代码已非常完善，无需强制修改。以下仅展示一种可选的微优化：
// 在 Reset() 中合并遍历逻辑（仅为演示风格，当前分离逻辑因 commitSync 阻塞更清晰）
void KeybindingManager::Reset()
{
    const QStringList resetIds = m_loader->resettableHotkeyIds();
    if (resetIds.isEmpty()) {
        return;
    }

    QStringList toRestore;
    for (const QString &id : resetIds) {
        if (!m_keyConfigsMap.contains(id)) {
            continue;
        }
        m_keyHandler->unregisterKey(id);
        m_specialKeyHandler->unregisterKey(id);
        toRestore.append(id);
    }

    if (!m_keyHandler->commitSync()) {
        qWarning() << "Reset: failed to commit unregistering existing hotkeys";
        return;
    }

    for (const QString &id : toRestore) {
        m_keyConfigsMap.remove(id);
    }

    m_loader->resetHotkeys(resetIds);
}