- cmd/codegen/main.go: drop "errors" stdlib import, use core.Is per Core convention
(non-WASM path).
- layout.go, path.go, responsive.go: add header notes documenting why these files
use stdlib (errors/strings/strconv) instead of core — RFC §7 caps WASM at
3.5 MB raw / 1 MB gzip, and dappco.re/go/core transitively pulls fmt/os/log.
- README.md, docs/index.md: migrate stale forge.lthn.ai/core/go-html module path
to canonical dappco.re/go/core/html; refresh dependency diagram and Go version.
All spec features are already implemented; this is spec-parity maintenance.
Verified: go build ./..., go vet ./..., go test ./... all green (WASM size test
back to 2.12 MB raw / 630 KB gzip after short-lived core-import regression).
Co-Authored-By: Virgil <virgil@lethean.io>
