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

mole

@@ -777,6 +777,9 @@ main() {
         "installer")
             exec "$SCRIPT_DIR/bin/installer.sh" "${args[@]:1}"
             ;;
+        "log")
+            exec "$SCRIPT_DIR/bin/log.sh" "${args[@]:1}"
+            ;;
         "touchid")
             exec "$SCRIPT_DIR/bin/touchid.sh" "${args[@]:1}"
             ;;