Add option to hide loaded context files banner on startup

Feature Request

When starting Claude Code, the CLI displays all loaded context files (MEMORY.md, CLAUDE.md, etc.) in the terminal. There's currently no way to suppress this display.

Requested Behavior

Add a setting or flag to hide the loaded context files banner at startup, while still loading and using them normally.

Why

• The banner adds visual noise for users who already know what context files exist
• --bare is the closest option but it disables too many features (hooks, auto-memory, CLAUDE.md auto-discovery, LSP, etc.)
• Users want a lightweight way to declutter the startup output without losing functionality

Suggested Approach

Either:

1. A CLI flag like --quiet that suppresses the context banner
2. A config setting like showContextBanner: false in settings.json
3. A --no-banner flag specifically for the startup display

Any of these would work — the key is suppressing the display without disabling the underlying features.