docs/plugins/sdk-entrypoints.md was ~40.8k characters. Split the eight
body sections into docs/plugins/sdk-entrypoints/, keeping the parent as an
index that retains the lede, Plugin shapes, Related, and MCP subprocess
runtime, and publishes an anchor map for every moved section.
Content-preserving: the extracted children reassemble byte-identically to
the original body (sha256 85426d06...). The one intra-page anchor link is
rewritten to its new target as a separate, enumerated change.
Extends TYPED_PUBLIC_CONTRACT_REFERENCE_FILES in
plugin-sdk-package-contract-guardrails.test.ts to the child pages so the
typed-public entrypoint guardrail keeps scanning the same material.
