Add deep linking support to open specific chats (e.g., vscode://anthropic.claude-code/chat/{chatId})

Problem

Currently, there's no way to programmatically open a specific Claude Code chat conversation in VS Code. This makes it difficult to:

• Build third-party tools/extensions that integrate with Claude Code chats
• Create workflows that jump to specific conversations programmatically
• Bookmark and return to important conversations quickly
• Reference chat sessions in local documentation or task trackers

Note: This feature request focuses on local chat navigation (chats stored in ~/.claude/projects/). For sharing chats with team members via git, see the related feature request #10368.

Proposed Solution

Add deep linking support using VS Code's URI protocol that would:

1. Open VS Code if not already running
2. Activate the Claude Code extension
3. Navigate to and display the specified chat conversation in the Claude Code panel

Proposed URI format:

vscode://anthropic.claude-code/chat/{sessionId}

Example:

vscode://anthropic.claude-code/chat/abc123-def456-789

Clicking this link would open that specific chat in the official Claude Code chat panel.

Alternatives Considered

• Manual navigation through chat history - Tedious for frequently referenced conversations, especially with many chats
• Copying chat transcripts - Loses interactive context and Claude Code's native formatting
• Third-party viewer extensions - Can read chat JSONL files but cannot open chats in the official Claude Code UI, limiting their usefulness
• Searching by chat title - Requires manual steps and assumes unique/memorable titles

Implementation Details

Technical approach:

• Leverage VS Code's vscode.window.registerUriHandler() API (already used by many extensions)
• Session IDs are already stored in the JSONL filenames: ~/.claude/projects/[project]/[session-uuid].jsonl
• No changes needed to storage format

Complementary features that would enhance this:

• "Copy link to chat" button in the chat interface
• Chat permalink generation in the chat history view
• VS Code command claude-code.openChat(sessionId) for programmatic access
• Documentation of the URI scheme for third-party integrations

Use cases:

• Personal workflow: Bookmarking important debugging sessions or architectural discussions
• Tool integration: Building custom dashboards or chat browsers that can jump to official UI
• Local documentation: Referencing specific chats in personal notes or local task trackers
• Agent integration: Local agents/scripts opening specific chats based on context

Related Features

• #10368 - Chat Package Export/Import for team collaboration
• #10370 - Chat Branching for side-chain conversations