Feature request: Persist /color setting across sessions

Feature Request

The /color command sets a color bar for the session, but it resets on every new login/session.

Current behavior

Running /color purple sets the color bar for the current session only. On next login, the color is gone.

Expected behavior

The color preference should persist across sessions, either by:

• A settings.json field (e.g. "sessionColor": "purple")
• Remembering the last used color automatically

Workaround

Currently there is no way to persist this — a SessionStart hook cannot invoke slash commands, so it cannot auto-set the color on session start.

Why it matters

Color bars are useful for visually distinguishing between different projects or contexts. Having to re-run /color every session is friction that undermines the feature's usefulness.