history

VT Resistance consolidates its project contract

id: LK-20260716-vt-resistance-project-spec
date: 2026-07-16
sequence: 90
type: refactor
compatibility: compatible
component: `labkit_VTResistance_app` | `1.4.1 -> 1.4.2`
scope: Electrochemistry
scope: Project lifecycle

Context

VT Resistance split static product metadata across three files and its first-version project across a generic lifecycle package. Its session factory also encodes a real performance policy by loading only the first preview source.

Decision and rationale

Make definition.m the complete product declaration and projectSpec.m the sole durable-schema entry. Keep createSession.m explicit because lazy DTA decoding and analysis is transient reconstruction, not lifecycle boilerplate.

Changes

Consolidated command metadata, version, update date, and requirements in the definition.
Consolidated project defaults and validation behind one project spec.
Moved lazy preview restoration to a package-root session factory.
Removed separate metadata files and the generic lifecycle package.
Added a direct project/session contract assertion to the VT export suite.
Kept pulse detection, steady windows, voltage definitions, resistance formulas, plots, and export schemas unchanged.

User and data impact

Launch, batch loading, selection, calculation, save/load, plotting, and CSV exports behave unchanged. The durable contract and lazy reconstruction policy are now explicit and adjacent.

Compatibility and migration

The project remains version 1 with identical fields, defaults, validation, and source records. Existing VT Resistance projects require no migration.

Validation

Unit tests cover project/session boundaries, pulse detection, window policies, raw and baseline-corrected resistance, failed rows, and CSV output. The hidden GUI workflow covers real launch, selection, calculation, save/load, plots, and export.

Evidence

Known limitations and follow-up

The lazy session still reaches into portable-reference internals. The shared source-path boundary will replace this across all Apps in one framework change.