# M12-02G Status

status: done
task: reclaim preview payload only after the final project-scoped reference is removed
updated: 2026-08-17 America/New_York
enablingTask: true
parityStateChange: false

## Scope

Preview reference removal is a guarded catalog mutation: it validates the v2 row, checks the exact
base revision, clears only the target asset's preview, advances revision, and commits a manifest
hash receipt. Payload reclamation happens only after that reference transaction has completed and
only when the committed manifest has zero remaining references to the content hash.

OPFS payload ownership remains project-scoped (`projects/<projectId>/assets/sha256/...`). Therefore
collection can target only the requested project's file and cannot delete an equal-hash payload
owned and referenced by another project. Non-preview asset metadata is preserved.

## Evidence

- `WEB_TEST_PORT=5599 npm --prefix web run test:asset-preview-reference-gc` passed the artifact unit
  test 1/1 and real Chromium OPFS/IndexedDB test 1/1.
- Project A began with two references to one deduplicated payload. Removing the first at revision
  9->10 returned `RETAINED`, one remaining reference, and kept the file.
- Removing the final reference at revision 10->11 returned `COLLECTED` and removed project A's
  payload. Project B's equal-hash payload remained present and its preview returned READY/513 bytes.
- Reopening project A reproduced revision 11, two null preview references, and unchanged metadata.

## Artifact Hashes

- reference GC: `76b9d8ccd3e7992356f33adc694001f9b0ff364788234389eacdb09198d1415e`
- Chromium suite: `2e9e9b47883997092c5afb0fb7859a484754764de19006e24a8ff2bdeb24f35a`
- unit suite: `c5de3122b5d8aab17daf0179cb4f5bb0b5d299408818849cbe7b18e40a47706e`
- manifest: `3449f2ea9488f66ea5e3f5f2423413e8e290d8ffed3b3d941bdeee3f76addd0a`
- package commands: `7d1db0932fbe7405ffdbd44b770ce7bf9815b9dfb829c1906a06bfff635ae702`

## Next Task

`M12-02H`: compare desktop/browser preview pixels with explicit metrics and pass both main-thread
and Offscreen display paths.

## Rollback

Remove the reference-GC protocol, Chromium/unit suites, M12-02G manifest, package command, and this
status entry. Restore M12-02G to pending and `nextTask` to M12-02G. Catalog and parity ledger data
do not require rollback.