fix(chat): allow intent confirmation in projectless personal chats

## Problem

`confirm_task_intent` cannot be approved in a projectless personal chat. The card receives `canWrite=false` and renders the project-role denial: “观察者可以查看这次复述，但不能替团队做确认.”

This blocks personal-chat skills that correctly request intent confirmation. In browser acceptance T62 (`帮我设计一次用户访谈的提纲`), the run reaches the confirmation card but the user has no Continue action after the card refreshes, even though the chat header says “不挂靠任何项目，仅自己可见”.

## Expected behavior

The owner of a projectless personal chat can confirm or edit that chat's own HITL request. Project role checks should apply only when a chat is actually attached to a project.

## Acceptance

- In a personal chat, the owner can approve and edit `confirm_task_intent`.
- In a project chat, observer denial continues to be enforced.
- T62 proceeds from confirmation to produce the requested interview outline.
- Regression tests cover both personal-owner and project-observer paths.

Source: WorkspaceX browser acceptance T62 from #3413.

Start by tracing the confirm_task_intent card's canWrite decision and the browser acceptance T62 flow. Verify that personal-chat owners can approve or edit the request while project observers remain denied, then add regression coverage for both paths and confirm T62 produces the interview outline.

Written by the indexing model from the issue text.