feat: add day of week to time result #2197

[zennur]

Description

This PR adds day of the week in the response model as text so that the agent would just need to map the language.

Server Details

• Server: time
• Changes to: capabilities

Motivation and Context

Resolves #2197
Identify day of the week from timestamp to avoid language conflicts

How Has This Been Tested?

✅ Server runs successfully with python -m python -m mcp_server_time.server
✅ Server can be instantiated and includes the new capabilities
✅ Code follows the same patterns used in the filesystem server's roots implementation
✅ Manual verification that the server identifies day of the week successfully

Breaking Changes

No breaking changes

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation update

Checklist

• I have read the MCP Protocol Documentation
• My changes follows MCP security best practices
• I have updated the server's README accordingly
• I have tested this with an LLM client
• My code follows the repository's style guidelines
• New and existing tests pass locally
• I have added appropriate error handling
• I have documented all environment variables and configuration options