feat(inbox-sweep): --state makes repeated sweeps idempotent

[hyperpolymath]

Follow-up to #123.

Why

GET /notifications?all=true also lists threads that are already done, and the REST notification object has no done field. I measured this live on hyperpolymath/HOL:

• inbox-sweep --apply --repo hyperpolymath/HOL cleared 4 of 4 due threads, and both DELETEs returned 204.
• PR docs: status truth refresh — repo exists, 7 moves, apply/App still open #7's subscription went true → 404, while open PR chore(deps): bump the actions group with 4 updates #11 stayed subscribed.
• The web inbox for that repo then showed only chore(deps): bump the actions group with 4 updates #11 (the positive control). The other four were gone.
• But all=true still listed all five threads unchanged three minutes later.

Without memory, every hourly run would therefore re-clear the same ~640 threads: about 1300 REST writes against a 5000/h budget that other sessions share.

What

--state <path> stores {thread id: updated_at}:

• An entry is recorded only after both DELETEs return 204. The file is written atomically (temp file + rename).
• A thread whose updated_at is unchanged is skipped before any GraphQL read or REST write.
• New activity, which GitHub uses to bring a done thread back to the inbox, makes it eligible again.
• Entries for threads that are no longer listed are pruned, so the file stays bounded.
• A missing file means empty state. A corrupt file exits 2: an empty state would silently re-clear everything.

Evidence

• just quality: exit 0, 310 passed, 0 failed.
• New tests: a second sweep using the saved state performs zero writes; a bumped updated_at is re-cleared; stale entries are pruned; the state file round-trips and a corrupt one is refused.
• Mutant: replacing the skip predicate with false fails 2 of the new tests.

🤖 Generated with Claude Code

https://claude.ai/code/session_0196aKTfvS6vPQVp2LPoXbjP

[coderabbitai]

Navigate logical layers of code changes, visualize relationships, and explore their blast radius.

Note

Currently processing new changes in this PR. This may take a few minutes, please wait...

⚙️ Run configuration

Configuration used: Organization UI

Review profile: ASSERTIVE

Plan: Advanced

Run ID: 04f29c49-8b73-49ba-a651-94eb80a31fe7

📥 Commits

Reviewing files that changed from the base of the PR and between 2f9434b and 0c39aa6.

📒 Files selected for processing (1)

• crates/squabble-cli/src/inbox.rs

 _______________________________________
< Goodbye, code review procrastination. >
 ---------------------------------------
  \
   \   (\__/)
       (•ㅅ•)
       / 　 づ

✨ Finishing Touches

📝 Generate docstrings

• Commit to this branch
• Create a new PR

• Autopilot · Keep fixing CodeRabbit findings and required CI, and resolving merge conflicts

Autopilot is currently an internal CodeRabbit preview.

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands.}