fix(migrate): apply roadmap special-case migration

Replace structural defer with hybrid: preserve previously translated
docs-cards moved into Completed projects (Signal debugging in DevTools,
Improve HMR, Zoneless Angular). Insert new English sections (AI experience,
Compiler, Reactivity, Components, etc.) for follow-up translation. Remove
deleted Future work section. Resolve textlint conjunction/joshi issues
in restored Japanese text.

Author: lacolaco