Windows cannot reliably execute the full Tauri lib test harness in CI because the process exits before Rust tests start in the desktop runtime loader path. Split the coordinator session state transitions into a Tauri-free Rust module used by coordinator.rs, and add a small Rust-only backend test crate that path-includes coordinator/hotkey/recorder/insertion logic for real Windows execution.
Constraint: User scoped this follow-up to backend-only Rust-to-Rust tests, not app/runtime smoke tests.
Constraint: Existing Windows CI still keeps full lib --no-run cfg/link coverage.
Rejected: Keep trying to execute cargo test --lib on Windows | it starts the full Tauri-linked test binary and fails before unit tests run.
Rejected: Rework release/runtime DLL handling | outside the backend unit-test scope.
Confidence: high
Scope-risk: moderate
Directive: Keep Windows actual unit execution on the Rust-only backend-tests manifest unless the full Tauri lib harness is proven runnable on clean Windows CI.
Tested: cargo test --manifest-path openless-all/app/src-tauri/backend-tests/Cargo.toml
Tested: cargo test --manifest-path openless-all/app/src-tauri/Cargo.toml --lib
Tested: cargo check --manifest-path openless-all/app/src-tauri/Cargo.toml
Tested: python yaml parse for .github/workflows/ci.yml; git diff --check
Not-tested: Windows runner execution; intended to be verified by GitHub Actions.
Related: #295
Co-authored-by: OmX <omx@oh-my-codex.dev>
