Improve session management: fix quoting and add expiration validation

[stephdl]

Overview

Improvements and fixes to the session management logic that was introduced in PR #1542.

Changes

🐛 Bug Fixes

1. Quote $session_start in expire command - Prevents word-splitting issues and ensures reliability with variable expansion
2. Validate session before extend - Check that session hasn't already expired before allowing extension, preventing extend operations on dead sessions

✨ Enhancements

3. Show session status after extend - Calls get_session_info after extend to provide immediate feedback on new expiration time
4. Improved validation comments - Add clarity to the extend logic

Details

Fix 1: Quoting in expire

# Before
session_start_time=$(cat $session_start)

# After
session_start_time=$(cat "$session_start")

Fix 2: Expiration validation before extend

extend)
    # Added validation block that checks:
    # - Session files exist
    # - Session hasn't already expired
    # Only then allows the 7-day extension

Enhancement: Feedback after extend

# Show updated session info after successful extension
get_session_info

Testing

All existing tests from the original PR still apply. Additional test cases to verify:

• ✅ Extend on expired session (should fail)
• ✅ Extend shows new expiration status
• ✅ All variables properly quoted

Related Issues

Fixes review feedback from PR #1542

[stephdl]

closed by #1554