Research try to use not existing tool "create" for file save

### Describe the bug

I use Copilot CLI. I made a research request. Results were printed in the console. I'm satisfied with the report, but the report could not be saved to the local disk. It tries to use a nonexistent tool "create": "Blocked item: I couldn’t save the report to
C:\Users\KanstantsinSudzilous\.copilot\session-state\5bf2e4e3-f93b-4f6e-a4b3-e35b52a8ae0f\research\excel-excel-template-pivot-table-data-3-2025-xlsx.md because the
create tool is not available in this session." Then in terminal I've made prompt "save this report to @docs\design\EXPORT_DEEP_RESEARCH.md" but it also failed, it was trying to use "create" tool that does not exist. Resolution was "save last research results report to @docs\design\EXPORT_DEEP_RESEARCH.md using tool apply_patch"

### Affected version

GitHub Copilot CLI 1.0.47

### Steps to reproduce the behavior

1. Make /research
2. Check the output it try to use a tool "create" to save report results

### Expected behavior

Expected to use apply_patch for file creation

### Additional context

_No response_

Start by reproducing the /research flow in Copilot CLI 1.0.47, then follow the save request for the generated report and the prompt targeting @docs/design/EXPORT_DEEP_RESEARCH.md. Confirm that file creation uses the available apply_patch tool rather than the nonexistent create tool.

索引モデルが issue の本文から書いたものです。