build: make standalone source builds reproducible

[0717lee]

Summary

Fixes #4.

• replace Harness-relative TypeScript and tsdown configuration with repository-local equivalents
• install the public rc.8 development packages from a pinned pnpm lockfile while preserving the existing runtime peer boundary
• reproduce the Host ESM, Web ModuleLoader bundle, CSS module injection, and declarations from a clean standalone clone
• normalize CSS module paths so build output does not depend on the checkout directory
• document the clean-clone workflow in English and Simplified Chinese

Verification

• corepack pnpm@11.7.0 install --frozen-lockfile
• corepack pnpm@11.7.0 verify
• repeated the frozen install and full verify in a second temporary directory with no node_modules
• confirmed both directories produced identical SHA-256 hashes for lib/index.js, lib/client.js, and both published declaration files
• imported lib/index.js and verified name, apply, and Config
• npm pack --dry-run contains the expected 9 release files

Scope

No runtime source or install policy changes are included. Publishing a new preview remains a maintainer release step.