Aligns module path with canonical Gitea source (infra ADR-0004) and repo name. Binary only, no downstream consumers. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01Roq1ajWKR5f1hG5Df9wC6A
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>