产品讨论：PR #254 fix(voice) 新增麦克风隐私同意前置

## 背景

PR #254 在麦克风启动前增加隐私同意流程，属于新增用户体验流程（而非单纯 bugfix），需要产品侧确认：

- 同意弹窗的触发时机与文案
- 拒绝后的降级行为
- 与系统级权限弹窗的衔接

## 关联 PR

- https://github.com/makecindy/cindy/pull/254

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关联 PR:#254(作者 @ganlingyao);本 issue 由 review-pr 流程自动创建,用于先讨论该 PR 涉及的产品 / UI 变更,聊清楚后 PR 会恢复审查。

Start by reviewing PR #254 and the product questions in this issue. Clarify the consent prompt timing and wording, the behavior after refusal, and how it connects to the system microphone permission dialog. Done means these decisions are documented so PR #254 can resume review.

Written by the indexing model from the issue text.