Continue Blender Web parity task handoff

docs/status/M16-GAP-00251.md

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+# M16-GAP-00251 Status
+
+status: done
+task: armature.select_hierarchy operator LOCAL_EXACT slice
+updated: 2026-08-23 America/New_York
+
+scope:
+
+- The minimal fixture contains a selected root, an unselected connected child,
+  and an independent unselected bone. Blender desktop runs
+  `ARMATURE_OT_select_hierarchy(direction=CHILD, extend=false)`, selecting the
+  immediate connected child and making it active without changing hierarchy,
+  visibility, or geometry.
+- WASM/Main reads the same fixture, including armature-space child coordinates
+  through `arm_head`/`arm_tail` with legacy `head`/`tail` fallback. The
+  comparator confirms desktop/WASM parity and save/reopen stability.
+
+evidence:
+
+- Fixture generation, desktop checker, npm comparator, direct comparator,
+  malformed-input negative, save/reopen check, production WASM rebuild, and
+  task-context handoff passed.
+- Repeated checker execution is idempotent (`SKIPPED_ALREADY_APPLIED` after
+  the first run); Chromium-only policy was preserved and no Firefox/WebKit run
+  was made.
+
+nextTask: `M16-GAP-00252`