Continue Blender Web parity task handoff

docs/status/M16-GAP-00257.md

@@ -0,0 +1,23 @@
+# M16-GAP-00257 Status
+
+status: done
+task: armature.select_similar operator LOCAL_EXACT slice
+updated: 2026-08-23 America/New_York
+
+scope:
+
+- The minimal fixture contains an active selected length-1 bone, an unselected
+  length-1 peer, and an unselected length-2 bone. Blender desktop runs
+  `ARMATURE_OT_select_similar(type=LENGTH, threshold=0.1)` and preserves the
+  expected selection and geometry through save/reopen.
+- WASM/Main reads the same fixture. The comparator confirms desktop/WASM parity,
+  malformed-input rejection without Main mutation, and save/reopen stability.
+
+evidence:
+
+- Fixture generation, desktop checker, npm comparator, direct comparator, and
+  repeated checker execution passed. The second checker run is idempotent
+  (`SKIPPED_ALREADY_APPLIED`); Chromium-only policy was preserved and no
+  Firefox/WebKit run was made.
+
+nextTask: `M16-GAP-00258`