feat(filesystem): add --ignore-write option to block writes to sensit…

[SOURABHMISHRA5221]

Title:
feat(filesystem): add --ignore-write option to block writes to sensitive files (#1869)

Description:
This PR addresses issue #1869 by adding a flexible mechanism to prevent accidental overwrites of sensitive files (such as .env) in the Filesystem MCP server.

Summary of changes:

• Added a --ignore-write <pattern1> <pattern2> ... command-line argument to the filesystem server.
• The server now blocks write operations to any file matching the provided patterns (supports globs like .env, .env.*, *.secret, etc.), even if the file is within an allowed directory.
• Updated the README.md to document the new option and provide usage examples.
• Improved security and user control over which files are protected from write operations.

Motivation:
Previously, the server could overwrite sensitive files (e.g., .env) without confirmation, risking data loss. This change allows users to specify which files should never be overwritten, improving safety and flexibility.

Testing:

• Manually tested with various ignore patterns and confirmed that write operations to matching files are blocked with an appropriate error.
• Verified that normal write operations to non-matching files still succeed.

Documentation:

• Updated README.md with usage instructions and security notes for the new --ignore-write option.

Checklist:

• Thoroughly tested changes
• Documentation updated
• Linked to issue Filesystem MCP server modified .env without permission and did not back it up #1869
• No breaking changes

[SOURABHMISHRA5221]

Hi @tadasant
Could you please review this PR when you have a chance? Thank you!

[SOURABHMISHRA5221]

Hi! @olaservo please review.