Add native buffered file subscriber

[brickfrog]

Summary

• Add the new brickfrog/moontrace/file package with a sync non-blocking subscriber, bounded async drain worker, flush/shutdown lifecycle, counters, size rotation, retention cleanup, and optional gzip for rotated files.
• Keep async and filesystem work confined to src/file with native implementation and clear unsupported-target lifecycle stubs for non-native targets.
• Add native timeout-bounded async tests for append ordering, rotation, retention, gzip round trip, bounded batching, overflow drops, and graceful shutdown; add docs showing app-owned worker wiring.

TDD

• Recorded tdd_intent for moontrace-cg9.6 file subscriber.
• Recorded red with a real overflow-counter mutation: the file-subscriber test failed with dropped count 0 != 2.
• Restored the implementation and recorded green, then done.

Verification

• moon fmt --check
• moon test --target native
• moon build --target native --release
• moon check --target all src/file
• moon info && moon fmt (no extra changes)

Verification

Generated by Choir from commands executed in the leaf workspace.

• moon fmt --check
  • exit: 0
  • head: a6a572c
  • output tail:

Finished. moon: no work to do

• moon test --target native
  • exit: 0
  • head: a6a572c
  • output tail:

Total tests: 272, passed: 272, failed: 0.

• moon build --target native --release
  • exit: 0
  • head: a6a572c
  • output tail:

Finished. moon: no work to do

[brickfrog]

Choir: GitHub Actions rollup reports all checks successful on the latest head — re-check review/merge policy on GitHub (not an approval or merge signal by itself).

[Copilot]

Pull request overview

Adds a new native-only buffered file subscriber package (brickfrog/moontrace/file) that provides a synchronous, non-blocking enqueue API and an app-owned async worker to drain events to disk with size-based rotation, retention cleanup, and optional gzip for rotated files.

Changes:

• Introduce src/file package with FileSubscriber + FileSubscriberConfig, async run/flush/shutdown, counters, rotation/retention, and gzip for rotated logs.
• Add native async tests covering ordering, rotation/retention, gzip round-trip, bounded batching, overflow drops, and shutdown behavior.
• Add user documentation describing intended wiring (app-owned worker) and rotation semantics.

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
src/file/pkg.generated.mbti	Exposes the new package API surface (subscriber constructor, lifecycle, counters, config).
src/file/moon.pkg	Declares async/fs/gzip/io dependencies for the new file subscriber package.
src/file/file_subscriber.mbt	Implements the native buffered file subscriber, worker drain loop, rotation/retention, gzip, and non-native stubs.
src/file/file_subscriber_test.mbt	Adds native tests validating ordering, rotation/retention, gzip, batching/overflow, and shutdown semantics.
docs/file.md	Documents how to wire the subscriber/worker and explains rotation + gzip behavior.

[brickfrog]

Choir: comment-only review received — routed to main.cg9-6-file-subscriber-1780317740000-22209-0 (leaf pane).

[brickfrog]

Choir: GitHub Copilot issue-thread comment observed on PR — parent notified with updated gate snapshot (not merge approval).

[brickfrog]

Choir: comment-only review received — routed to main.cg9-6-file-subscriber-1780317740000-22209-0 (leaf pane).

[brickfrog]

Choir: fixes pushed by main.cg9-6-file-subscriber-1780317740000-22209-0 — resolving threads and checking gates (not merged yet).

[brickfrog]

Choir: GitHub Actions rollup reports all checks successful on the latest head — re-check review/merge policy on GitHub (not an approval or merge signal by itself).

[brickfrog]

Choir: fixes pushed by main.cg9-6-file-subscriber-1780317740000-22209-0 — resolving threads and checking gates (not merged yet).

[brickfrog]

Choir: GitHub Actions rollup reports all checks successful on the latest head — re-check review/merge policy on GitHub (not an approval or merge signal by itself).