Align langgraph-js with examples/integrations/langgraph-python via the
parity tooling. Remove legacy app/ layout, adopt src/ layout, rewrite
the TS agent to expose the tracked tool surface (manage_todos,
get_todos, query_data, generate_a2ui, search_flights) and todos state,
and write the canonical PROMPT.md. Keeps LangGraphAgent + stategraph
runtime (allowed divergence per the manifest); brings deps,
Dockerfile.app, entrypoint, showcase metadata, and shared UI into
lockstep. Parity verifier: 88 ok / 0 error.
Ran Shem Tov