Add "retrospective" to validPhases so non-TDD skills pass Validate().
Return []Entry{} instead of nil in session.Read when no file exists,
so JSON serialisation produces [] rather than null.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
- Replace deprecated os.IsNotExist with errors.Is(err, fs.ErrNotExist)
- Capture Close error in Append by calling it explicitly instead of defer
- Increase scanner buffer to 1 MB per line to handle large JSONL entries
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Introduces internal/session with Entry and Attempt types, Append
(O_APPEND JSONL writer) and Read (line scanner, nil on missing file).
Raw material for retrospective and trainer workers.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
