Release unused file buffers for empty artifacts

docs/roadmap/remediation.md

@@ -1,7 +1,6 @@
 # Implementation Review Remediation
 
-Status: One computational-efficiency finding awaits remediation. Earlier
-findings below remain resolved.
+Status: All recorded findings have been resolved in separate remediation units.
 
 ## Computational Efficiency Review
 
@@ -10,7 +9,16 @@ Review baseline: `8a5c0de`, compared with planning commit `3fde1f6`, the
 
 ### Finding 1 — Release A Stale File Reservation For An Empty Body (P3)
 
-**Status: Open.**
+**Status: Resolved.** Completed empty bodies now release stale file-size
+reservations using the existing compaction path. The stale-size table covers
+empty content, metadata, and hashes; the retained-artifact benchmark includes
+an empty-body fixture without enforcing capacity or allocation thresholds.
+Three offline, one-iteration samples for four retained empty artifacts changed
+from 4,194,928–4,194,976 retained bytes to 624–640 bytes. Initial reservation
+allocations still occur; this fix reduces retained storage, not cumulative
+allocation. The nonempty benchmark remains near 1 MiB for four 256 KiB bodies.
+Artifact package race tests and vet passed, and the internal documentation
+now accurately describes the compaction condition.
 
 Location: [file reader](../../internal/artifact/reader.go), lines 137–166.