Add comprehensive e2e tests for --max-chars output truncation

[jancurn]

Summary

This PR adds a comprehensive end-to-end test suite for the --max-chars option, which controls output truncation in human-readable mode while being ignored in JSON mode.

Key Changes

• New test file: test/e2e/suites/basic/max-chars.test.sh with 192 lines of test coverage
• Test coverage includes:
  • Output truncation behavior for tools-call, tools-list, resources-list, resources-read, prompts-list, and prompts-get commands
  • Verification that truncation messages display correctly with character counts and size indicators (chars/KB)
  • Confirmation that --max-chars is properly ignored when using --json mode
  • Input validation tests for invalid values (zero, negative, non-numeric)
  • Edge cases like small vs. large output and small vs. large --max-chars values

Notable Implementation Details

• Tests verify both truncation behavior (output is cut off) and user feedback (truncation notice is displayed)
• Tests confirm that JSON output is never truncated regardless of --max-chars setting
• Comprehensive validation testing ensures the option rejects invalid inputs with appropriate error messages
• Tests use the existing test framework (framework.sh) and follow established patterns for session management and assertions

https://claude.ai/code/session_01ExKTHAP8ADz2QfXi1vYh5p