[FEATURE] Add /fork (conversation branching) support to VS Code extension

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

The CLI supports conversation forking via --fork-session (and /fork slash command), allowing users to branch a conversation at any point and explore a different direction while preserving the original session. This capability is available by clicking on a previous message, but this creates an issue where the context is lost when the message is far back in the conversation.

Proposed Solution

/fork slash command available in the VS Code extension prompt box (alongside existing commands like /compact, /usage, etc.)

Forked session appears as a new tab, preserving full conversation history up to the fork point.

This will allow the user to fork the message at that current point instead of going far back in the history and losing valuable context.

Alternative Solutions

_No response_

Priority

Medium - Would be very helpful

Feature Category

CLI commands and flags

Use Case Example

_No response_

Additional Context

PLEASE add this! This would be very useful!

Often times I send a message and then Claude will send many, many messages and context back so it would be nice to "/fork" from that current point instead of clicking on that message I sent a long time ago to "fork conversation from here"