M2 in-cell visual encodings and sparkline consolidation

Problem

Standardize in-cell bar and sparkline configuration under the table formatting model, including compatibility with existing spark support.

Context

• Existing spark support and new in-cell visual ideas risk diverging into separate inconsistent APIs.
• Table formatting needs one coherent model for small embedded visuals such as bars and sparklines.
• The solution must fit table rendering constraints and remain authorable without raw renderer details.

Possible Solutions

• A - Keep sparkline support separate and add bars as another one-off option: easiest incrementally, but messy.
• B - Expose a very generic embedded-chart surface inside every cell: powerful, but likely too unconstrained.
• C - Recommended: define one table visual encoding model that standardizes bars and sparklines under shared configuration and rendering rules.

Plan

1. Inventory current spark support and the desired in-cell visual use cases.
2. Define a unified schema for supported visual encodings and shared defaults.
3. Align renderer behavior and migration rules for any existing spark configuration.
4. Add examples and tests for bars, sparklines, and unsupported edge cases.

Implementation Progress

QA Exploration

• [ ] QA exploration completed (or N/A for non-UI tasks)

Review Feedback

• [ ] Review cleared