docs/research/QVM_RETURN_PLACEMENT.md

Fail-closed CALL return placement and coherent result bytes

RE-781. Reproduce with python3 scripts/analyze_qvm_return_placement.py; validate with cargo xtask test-group return-placement. See the machine report.

Forty executable witnesses cover direct/dynamic callbacks, every byte lane, signed negative and high-bit words. The shared trace resumer infers only the immediate LOCAL/CONST/CALL/STORE4 pattern and rejects ambiguous dynamic stores without a reviewed explicit offset. A reusable patch helper updates both word and little-endian byte views before resuming. Original sort callback35229 already supplies offset80. The movement resumer migration and repeated-call audit remain separate tasks.

No original executable/full VM/native world collision or rendering runs. Supplied callback/native responses and fixture domains remain explicit; complete macOS/Linux Rust/Bevy/Solari gameplay remains open.