fix(agent-core-v2): tolerate stray files in the sessions directory during index scans

[zhi1ong]

Related Issue

Resolve #3500

(Filed with this PR; awaiting a maintainer's /approve.)

Problem

On 0.40.x the resume picker (kimi -r, /sessions) and kimi session list list no sessions at all when any workspace bucket directory under ~/.kimi-code/sessions/ contains a stray regular file — macOS Finder's .DS_Store is the common trigger. The scan added in #3422 stats <entry>/state.json for every entry of every bucket directory; for a regular-file entry that fails with ENOTDIR, which the node-fs storage translated to StorageError(io_failed) ("storage stat failed: unrecognized I/O error"), rejecting the whole scan. Projection, startup freshness checks, periodic reconciliation, and the authoritative fallback read all fail, so fresh processes cannot list any session. Long-running servers degrade into a per-entry-tolerant branch and keep working, which makes the failure look like frontends see different session sets.

What changed

• node-fs storage: isEnoent is now isMissingEntry and also matches ENOTDIR. A regular file in place of a scope directory means the probed key cannot exist, so read, readStream, list, delete, size, and mtime report it as missing instead of throwing. This fits the existing storage contract ("undefined = missing"), heals every session-index scan path through one seam, and matches the in-memory backend, where probing a path below a value already resolves to missing.
• Alternative considered: per-entry catches inside the session-index scans. Rejected — it patches only the session domain while other storage consumers stay fragile, and swallowing arbitrary stat errors there could mask real corruption; the storage layer is where ENOENT semantics already live.
• Test: regression case covering a regular file in place of a scope directory for all probe operations.
• Changeset: patch entry for @moonshot-ai/kimi-code.

Checklist

• I have read the CONTRIBUTING document.
• I have linked a related issue (external PRs: the issue must have a maintainer's /approve).
• I have added tests that prove my feature works.
• Ran gen-changesets skill, or this PR needs no changeset.
• Ran gen-docs skill, or this PR needs no doc update.

[changeset-bot]

🦋 Changeset detected

Latest commit: 7c25b1b

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
@moonshot-ai/kimi-code	Patch

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[chatgpt-codex-connector]

Codex Review Summary

This comment shows the latest Codex review activity on this pull request.

Review	Status	Commit	Review trigger
📝 Code Review	✅ Completed 2026-09-03T04:58:12.372110Z	7c25b1b	PR opened

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[zhi1ong]

#3618 is a better fix: it handles this at the session index layer, where the knowledge that stray entries are expected belongs, and it logs the offending path. Generalizing ENOTDIR to ENOENT across the whole storage contract would mask path-construction bugs elsewhere. Closing in favor of it.