UI Harden

Make the interface survive reality, not only the ideal demo.

Establish the contract

Identify:

• the target path and primary task;
• the source context and the target context, including where, how, and for how long the product is used;
• supported devices, browsers, platforms, and input methods;
• realistic data ranges and content extremes;
• known network, authentication, permission, and concurrency behavior;
• localization and accessibility requirements;
• measurable performance symptoms, if performance is in scope.

Infer from the repository and existing tests before asking. Do not invent backend behavior or supported environments.

Read references/resilience-matrix.md and select the applicable scenarios. If the task changes device, viewport, input, platform, or delivery context, also read references/adaptation-patterns.md. If measured or suspected performance is in scope, read references/performance-diagnostics.md.