[FEATURE] Add "Allow for Session" permission option to Claude Code Desktop

Summary

Add Allow for Session as a permission option in Claude Code Desktop's tool approval dialog — something the VS Code Claude extension already supports.

Current behavior (Desktop)

When a tool requires approval, Claude Code Desktop offers two buttons:

• Allow Once — one-time approval
• Always Allow — persists to the project's .claude/settings.local.json

There is no way to grant a permission for the current session only.

VS Code extension (for reference)

The VS Code Claude extension also shows two buttons, but the second button can be toggled between Allow for Session and Allow for Project. So from a single prompt the user can pick:

• Allow Once
• Allow for Session (default of the second button)
• Allow for Project (the other toggle state)

This gives three effective tiers without adding a third button.

Requested behavior

Bring the same capability to Desktop — ideally via the same toggle pattern on the second button, so users can choose between session-scoped and project-scoped trust when approving a tool. The exact UI is up to the team; what matters is that Allow for Session becomes reachable from the approval dialog.

Use case: granular trust without polluting settings.local.json

Session-scope fills a real gap between one-time and project-wide trust:

• I frequently want to approve a tool for the duration of the current work session without committing it to the project's persistent permission list. With only the binary choice on Desktop today, I either click "Allow Once" dozens of times per session or accumulate entries in settings.local.json that I'd rather not persist.
• For exploratory work or debugging, session-scope lets me move quickly without making long-term commitments about what the project is allowed to do.
• settings.local.json stays cleaner — fewer ad-hoc entries means less manual cleanup later.

In VS Code this is my most-used option, and I'd expect the same on Desktop once available.

Environment

Claude Code Desktop on Windows 11.