Rust protected progress and completion primitive

RE-743. Reproduce with python3 scripts/analyze_rust_protected_update.py; validate with cargo xtask test-group gameplay. See the machine report.

Added pure Rust ProtectedState/update with source-order float32 conversion and explicit unsupported conversion errors. A scoped executable compares exact output words against the complete protected source fixture set; four Rust unit tests cover threshold, truncation, negative clamp and invalid domains. Event allocation, attacker state copying and callbacks remain caller responsibilities. The impulse report test now checks its minimum owned test count because the gameplay crate contains additional tests.

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.