cli/explore: resumable output + run manifest

[guillon]

Motivation

Long-running loop-explore sessions are currently brittle when interrupted:

• output CSV is opened in overwrite mode by default, so recovering partial runs is manual;
• there is no run manifest to capture arguments/runtime/git revision for reproducibility.

This change improves resilience and provenance while keeping the default behavior backward compatible.

Description

• add --resume mode to append and skip already-recorded (backend, sample) rows;
• add --append mode to append without deduplication;
• enforce --resume and --append mutual exclusion;
• write <output>.meta.json run manifest with args, python/runtime info, timestamp, and git commit hash;
• make CSV writes more crash-safe with flush + fsync;
• update CLI tutorial with resume/append workflow examples.

Commits

• cli/explore: add resume+append output handling and run manifest

Discussion

Fast coverage plan (proposal):

• add a focused unit test for CSV resume dedup logic (small synthetic CSV + callback writes);
• keep tests file-local and deterministic (no backend compile/run).

TODO:

• add unit test for resume dedup key handling

---

Father proposed this change
Father prototyped this change
Father pushed this change

[guillon]

Father,

please Update given comments and:

• update TODO
• no need to test exclusive options --resume and --append

Squash commits into a single commit before updating.

[guillon]

Father,

please Update given comments and:

• update TODO
• no need to test exclusive options --resume and --append

Squash commits into a single commit before updating.

[guillon]

@liamsemeria for information