Replace hand-written serialize/sx_serialize/sx_parse in Python with
spec-derived versions from parser.sx. Add parser as a Python adapter
alongside html/sx/async — all 48 parser spec tests pass.
Add reactive runtime plan to sx-docs: 7 feature layers (ref, foreign
FFI, state machines, commands with undo/redo, render loops, keyed
lists, client-first app shell) — zero new platform primitives.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
giles
4b746e4c8b