[FEATURE] Support multiple IDE selections in conversation context (ide_selection)

Preflight Checklist

• [x] I have searched existing requests and this feature hasn't been requested yet
• [x] This is a single feature request (not multiple features)

Problem Statement

Problem

The VS Code extension ide_selection tag only carries a single selection into the conversation. When a user selects code in multiple locations and sends a message, only the first (most recent) selection is included.

Expected Behavior

Allow multiple code selections to be referenced in a single conversation turn, either by:

1. Supporting multiple <ide_selection> blocks in the conversation context
2. Or including all active editor selections in a single block

Proposed Solution

Use Case

When asking Claude to refactor code that spans multiple files or locations, users currently have to paste each code snippet manually into the message body, which breaks the natural selection → ask workflow.

Alternatives Considered

Users can work around this by pasting code directly into the message, but this requires extra steps and removes the visual context of the IDE selection.

Alternative Solutions

_No response_

Priority

Critical - Blocking my work

Feature Category

CLI commands and flags

Use Case Example

_No response_

Additional Context

_No response_