Feature: Renameable session tabs in VS Code extension

Problem

When working with multiple Claude Code sessions in VS Code, tabs are identified by a truncated snippet of the first message. With many sessions open (20+), it's impossible to tell them apart at a glance.

Proposed Solution

Allow users to rename session tabs for easy identification. A few approaches:

1. Right-click → "Rename Session" on the tab
2. Slash command like /name "Otto audit fixes" to label the current session
3. Auto-naming from context — derive tab name from git branch, working directory, or first significant topic

Why This Matters

Power users who work across multiple tasks (different features, bugs, explorations) end up with many sessions. The current truncated-first-message naming makes it hard to:

• Find a specific session to resume
• Distinguish between related sessions
• Know which sessions are stale vs. active

Workaround

Using /handoff to persist context and closing stale sessions, but this loses the convenience of quick tab switching between active workstreams.