[Sankey] Style Sankey nodes and links

[mossy426-cdc]

Story Key: sankey-view:style-rendering

User Story

As a MicrobeTrace user, I want to style the Sankey view from uploaded data and controls, so that I can visually distinguish data categories and preserve presentation choices.

Workflow / Use Case

Apply style files, color mappings, or styling controls to covered datasets and verify the Sankey view reflects the selected visual encoding.

Expected Behavior

Sankey applies covered colors, labels, sizes, shapes, and style-table edits consistently through filtering, grouping, timeline, and restore paths where applicable.

Acceptance Criteria

• Given the linked QA tracker scenarios, when the user performs the covered Sankey workflow, then the expected behavior remains true for each listed fixture and spec.
• Given the listed Cypress specs are run, when they pass, then this story has automated evidence for the grouped acceptance checks.
• Given linked QA evidence changes, when this story is regenerated, then tested fixtures, specs, and coverage notes stay aligned with the current QA trackers.

QA Tracker Evidence

• sankey-view:S010
• sankey-view:S019
• sankey-view:S020

Tested Against

Fixtures

• TestStyleNodelist_snp.csv
• TestStyleEdgelist_snp.csv

Cypress Specs

• cypress/e2e/journeys/flows/sankey-controls-uploaded.cy.ts

Coverage Notes
Grouped from 3 QA tracker row(s): Uniform link color and font-size controls on uploaded data; Source and Target link-color modes; Per-layer color edits update nodes and derived link colors. Source areas: Styling.

Source References

• User story row: docs/user-stories.csv#L94
• Branch: dev
• Commit: f4b481eb2242d2a89251300c3b94eaf09c842e04
• Generated by: mossy426-cdc
• Epic / Feature Group: Sankey
• Story Type: Settings/Controls
• Priority: P1
• Story Review Status: Draft
• Source Confidence: High
• Last reviewed: 2026-04-22

Story Notes

Generated as a grouped user story from QA tracker evidence. Review title and behavior language before enabling story_sync.

Definition of Done

• Acceptance criteria are satisfied.
• Linked QA tracker evidence remains current.
• Relevant Cypress coverage remains passing or any coverage gap is documented.
• Expected behavior remains distinguishable from bug or enhancement requests.

Manual Notes

Reviewer notes added below this line are preserved by future sync runs.