history

Chrono Overlay removes App-owned source identity bookkeeping

id: LK-20260716-chrono-runtime-source-reconciliation
date: 2026-07-16
sequence: 111
type: fix
compatibility: compatible
component: `labkit_ChronoOverlay_app` | `1.4.3 -> 1.4.4`
scope: Electrochemistry
scope: App structure
scope: Project identity

Context

Chrono Overlay generated a new source ID from the current record count. After removing an earlier source, adding another file could therefore reuse an ID still owned by a retained record. Runtime validation correctly rejects duplicate IDs, but the App should not have been maintaining this persistence invariant itself.

The App also duplicated source append/removal helpers and empty transient workflow/view buckets already supplied by Runtime V2.

Decision and rationale

After every successful add, removal, or clear operation, derive the ordered path list from the decoded items and delegate durable-record reconciliation to services.project.reconcileSources. Chrono Overlay continues to own decoding, pulse-gap alignment, item order, selection, logs, and failure wording. Runtime owns stable identity reuse and collision-free allocation.

Only App-specific selection and decoded cache data are returned by createSession; Runtime canonicalizes the remaining transient buckets.

Changes

Removed App-local source record append, removal, and count-based ID logic.
Reconciled source records from the accepted decoded item order.
Removed empty workflow and view boilerplate from the session factory.
Replaced the dynamically growing failure list with one first-failure record while retaining per-file log messages.
Added a GUI regression sequence that removes the first of two sources, adds it again, checks unique IDs, saves, clears, and reopens the project.
Advanced the Chrono Overlay App version to 1.4.4.

User and data impact

Normal file loading, ordering, selection, plots, exports, and saved project payloads retain their behavior. The remove-then-add sequence no longer risks a duplicate source ID and failed callback. Persistence IDs remain internal and do not change curve values or scientific output.

Compatibility and migration

The current payload remains version 2 and no new migration is needed. Existing records retain their IDs when their paths remain in the project.

Validation

The Chrono Overlay hidden GUI workflow covers two-file loading, selection, remove and re-add, unique identity, export, save, clear, reopen, option redraw, and final plot clearing. Focused unit, structure, version, documentation, and history tests protect the calculation and product contracts.

Evidence

Known limitations and follow-up

CIC, CSC, and VT Resistance still have equivalent App-local source identity helpers and require their own ordering and behavior audits before conversion.