[FEATURE] Make ALL System Reminder message types OPTIONAL individually

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

System Reminders may be useful but YOU KEEP BREAKING THEM killing basic functionality and context usage limits along with CONFUSING Claude by poisoning the context with USELESS INFORMATION.

Make all the different types of System Remind messages toggleable by the user so we can have our OWN MCPs handle those kinds of things. Just like you finally gave us the option to COMPLETELY replace the System Prompt. Your hidden System Reminders have been a MAJOR CAUSE of problems since DAY ONE of Claude Code. Being able to disable them selectively or in total would prevent so many problems I've run into I can't even list them all.

Proposed Solution

--no-system-reminders

and/or

a /system-reminders command with the ability to toggle off each category of system reminder you have.

Alternative Solutions

_No response_

Priority

High - Significant impact on productivity

Feature Category

Interactive mode (TUI)

Use Case Example

System Reminders telling Claude code a file was modified externally. Great in theory BUT YOU DUMP THE ENTIRE FILE CONTENTS INTO CLAUDE CONTEXT EVERY TIME IT DOES THIS. THAT is a problem both in WASTING OUR USAGE LIMITS and in POISONING CLAUDES CONTEXT.

Additional Context

_No response_