Applies a transparent heuristic: cycle fade scales with equivalent full cycles and depth-of-discharge exponent; calendar fade scales with square-root time and a temperature factor. Coefficients are caller supplied or declared defaults. This is not cell-chemistry validation, warranty advice or a safety prognosis.

Canonicalizes device_id, nonce and message, computes an HMAC-SHA256 tag with caller-supplied ephemeral key material, and optionally compares a claimed tag in constant time. It does not provision devices, store keys or replace asymmetric device identity; do not submit long-lived production secrets.

Groups caller-supplied scalar field changes by field name, selects the highest version, and reports a conflict when equal-version values differ. It does not connect to a twin platform, merge nested documents or resolve semantic conflicts.

Computes free-space loss at one metre, applies a caller-supplied path-loss exponent over distance, then reports estimated receive power and margin against receiver sensitivity. This planning estimate does not model terrain, Fresnel obstruction, interference, antenna mismatch or regulatory duty cycle.

Canonicalizes firmware hash, version, device model and minimum bootloader version, then produces a SHA-256 manifest digest and HMAC-SHA256 release tag using caller-supplied ephemeral key material. This is a symmetric integrity tag, not a vendor PKI signature or code-signing service.