Python a2ui_agent: Support custom cuttable keys configuration

[nan-yu]

It follows up internal discussion in https://chat.google.com/room/AAQAA_wnJC4/s8Cir-DWpYA/s8Cir-DWpYA?cls=10.

Instead of using a hard-coded set of cuttable keys for auto-healing during stream parsing process, it allows configuring a set of custom configuration keys.

Summary of Changes

This pull request enables configurable cuttable keys for the A2UI streaming parser, moving away from a hard-coded set. This change allows users to define custom keys that can be safely auto-healed during stream processing, improving robustness for varied data structures. The implementation spans the core catalog configuration, SDK logic in both Kotlin and Python, and updated conformance tests to ensure consistent behavior.

Highlights

• Custom Cuttable Keys Configuration: Introduced support for configuring custom cuttable keys in the A2UI catalog, allowing for more flexible auto-healing during stream parsing.
• Schema and SDK Updates: Updated the conformance schema and both Kotlin and Python SDKs to support the new custom_cuttable_keys configuration property.
• Conformance Testing: Added new conformance test cases to verify that custom cuttable keys are correctly preserved and respected by the streaming parser.

Activity

• Initial pull request created by nan-yu.
• Automated review feedback provided suggestions for improving default value handling for cuttable keys and simplifying constructor calls.
• The author has addressed the feedback to ensure consistent behavior when no catalog is provided.

[gemini-code-assist]

Code Review

This pull request introduces support for custom cuttable keys in both the Kotlin and Python SDKs, allowing users to configure which keys can be safely auto-closed when fragmented in a stream. The changes include updates to the conformance schema, suites, catalog configurations, and streaming parsers. The review feedback highlights critical regressions in both Kotlin and Python where the parser defaults to an empty set of cuttable keys instead of the default set when no catalog is provided. Additionally, several improvements are suggested to simplify redundant conditional logic when instantiating catalogs and configurations.

[nan-yu]

/gemini summary

[gemini-code-assist]

Summary of Changes

This pull request enables configurable cuttable keys for the A2UI streaming parser, moving away from a hard-coded set. This change allows users to define custom keys that can be safely auto-healed during stream processing, improving robustness for varied data structures. The implementation spans the core catalog configuration, SDK logic in both Kotlin and Python, and updated conformance tests to ensure consistent behavior.

Highlights

• Custom Cuttable Keys Configuration: Introduced support for configuring custom cuttable keys in the A2UI catalog, allowing for more flexible auto-healing during stream parsing.
• Schema and SDK Updates: Updated the conformance schema and both Kotlin and Python SDKs to support the new custom_cuttable_keys configuration property.
• Conformance Testing: Added new conformance test cases to verify that custom cuttable keys are correctly preserved and respected by the streaming parser.

Activity

• Initial pull request created by nan-yu.
• Automated review feedback provided suggestions for improving default value handling for cuttable keys and simplifying constructor calls.
• The author has addressed the feedback to ensure consistent behavior when no catalog is provided.