feat: optimize log system and add mo log command

- Add get_timestamp() helper and optimize log rotation
- Create mo log viewer with search/filter capabilities
- Improve test coverage to 18.4% with better assertions
- Add security fixes for grep injection prevention

.gitignore

@@ -69,5 +69,10 @@ tests/tmp-*/
 tests/*.tmp
 tests/*.log
 
+# Go test coverage files
+*.out
+coverage.out
+coverage.html
+
 session.json
 run_tests.ps1