Fresh-session handoff

Purpose: finish or review one bounded Sensor Monitor change using the repository alone. Begin with AGENTS.md, README, requirements, the exact source diff and the dependency manifest. The current final source implements synthetic acquisition, normal/alert/fault policy, bounded commands, JSON Lines output, replay and native tests.

Establish the current state with git status --short and the applicable native test command. Use the replay fixture named in the task; capture output and exit status. Cross-build any firmware/shared-source change with the manifest FQBN. Inspect the resulting diff and confirm no unrelated files changed. Record what you ran, the current source hash/commit and the limits of the result; if a command cannot run, state the missing dependency.

Fresh-session exercise: in a new disposable CP08 folder, add an assertion proving that negative infinity enters FAULT/nonfinite with no current temperature, leaving production behavior unchanged. Read the requirements; compare with the existing NaN and positive-infinity cases. Run the basic host tests, show the small diff and write a short evidence note. CP08 has no configurable threshold/hysteresis/parser feature; implement those only in the Chapter 17 capstone.

The firmware generates synthetic values and has no physical sensor driver. Board revision, wiring, serial passthrough, upload, indicators and sensor accuracy remain unverified. The optional deployment plan is documentation, not a receipt. No paid API or account secret is part of this handoff.