Refactors log rendering to print errors to stderr and continue processing on JSON parse or rendering failures, instead of returning early. Updates tests to check both stdout and stderr outputs, and adds new test cases and testdata for tolerant parsing and error scenarios.
Shell commands in log output are now prefixed with '$ ' for improved readability and consistency with common shell output conventions. Updated related test data and test helper comments to reflect this change.
Renamed sample log input and expected output files in testdata to use a consistent 'log-*-input.txt' and 'log-*-want.txt' naming scheme. Updated references in log_test.go to match the new file names for improved clarity and maintainability.
