Flip the 4 TS a2ui builders (shared/typescript + mastra,
claude-sdk-typescript, langgraph-typescript) from the legacy flat
operation shape to v0.9 nested (createSurface / updateComponents /
updateDataModel), matching the Python builder and what A2UI consumers
process. Flat ops were never processed as valid nested operations, so
the surface schema and components were never applied.
Also align the empty-data guard to Python's `if data:` semantics (empty
object -> no updateDataModel), add a v0.9 parity guard test to all 4
test files, and add 12 gen-ui-a2ui-fixed aimock fixtures.
Replace sys.path.insert hacks in Python agent files with direct
imports via symlinks to shared/{python,typescript}/tools.
Update Dockerfiles, entrypoints, and configs to support the new
symlink-based tool resolution. Add PARITY_NOTES for frameworks
that have known gaps.