v1.2 release and migration readiness

Problem

The v1.2 release will include changes to chart interaction behavior, accessibility attributes, and potentially visual defaults that existing dashboards depend on. Without migration readiness — documented breaking changes to interaction patterns, upgrade guidance for dashboards that rely on deprecated tooltip/hover behavior, and clear communication of what changed and why — users will experience silent behavior changes in their existing dashboards after upgrading. This is particularly dangerous for interaction and accessibility changes, where "it looks the same but behaves differently" can break workflows and accessibility compliance without any visible warning.

Context

• Deeper or changed behavior in visual language, chart defaults, interaction behavior, and differentiated styling often creates migration work for users, operators, or downstream systems, and that work is easy to underestimate until release time.
• This task should make the release path explicit: what is changing, who is affected, what needs communication or tooling help, and how rollback would work if adoption goes sideways.
• Expected touchpoints include dataface/core/render/chart/, chart design docs, examples, and visualization test coverage, release notes, migration docs, compatibility checks, and any support/runbook surfaces that will absorb the change.

Possible Solutions

• A - Treat release readiness as a final checklist after implementation: simple, but it often surfaces migration risk too late to respond well.
• B - Recommended: plan release and migration alongside the feature depth work: document contract changes, compatibility handling, communication, and rollback before the release window.
• C - Force all users onto the new behavior with minimal migration help: faster to ship, but costly in trust and support load.

Plan

1. List the behavior, contract, or configuration changes in visual language, chart defaults, interaction behavior, and differentiated styling that could affect users, operators, or downstream consumers.
2. Define the migration path, release notes, compatibility expectations, and any temporary bridges or tooling needed for safe adoption.
3. Confirm the rollback and support posture for the riskiest changes and make sure the release owner surfaces are documented.
4. Review the plan against the actual implementation scope and create follow-up items for anything that cannot safely make the release cut.

Implementation Progress

Review Feedback

• [ ] Review cleared