Update skills for Partial Prefetching (#96299)
## Summary
- update the Partial Prefetching adoption skill for the current runtime
prefetching model
- scope the Cache Components optimizer's runtime-prefetch limitation to
URL data
- preserve the optimizer pattern structure for URL data that cannot
move, with Partial Prefetching, targeted `<Link prefetch={true}>`, and
cached URL-data content as the requirements
- make the optimizer follow-up conditional: use targeted
`prefetch={true}` when the app already adopted Partial Prefetching,
otherwise recommend the PPF adoption skill for the broader shared App
Shell model
## Why
Andrew's Partial Prefetching work removes the old `allow-runtime`
route-config model. The skills should teach the current shape: Partial
Prefetching gives links a shared App Shell baseline with lower
duplicated prefetch cost, while `<Link prefetch={true}>` is reserved for
links where resolving URL-specific content before click is worth the
extra server work.
## Validation
- `git diff --check HEAD~1..HEAD`
- grep confirmed no `allow-runtime` / `force-runtime` references remain
in the changed Skill files
- attempted `skill-creator` quick validation, but the local Python env
is missing `yaml`
