feat: complete week-one launch readiness - #18

Summary

• launch the hosted CauseScope documentation experience, StackBlitz lab, social preview, and clearer English/Chinese onboarding
• validate the packed public API against Vite 5.4, 6.4, 7.3, and 8.1, including original TSX source-map preservation
• add GitHub Pages deployment, compatibility CI, security automation, and the 1.0.0-beta.2 release baseline
• update React 19 to Vite 8, retain React 18 browser coverage on Vite 6, and make source opening editor-agnostic
• harden the development dependency baseline with patched Vitest, Vite, VitePress, and Vite 8 esbuild versions

Validation

• pnpm check
• CAUSESCOPE_DOCS_BASE=/causescope/ pnpm docs:build
• packed tarball consumed by Vite 5.4.21, 6.4.3, 7.3.6, and 8.1.5
• clean-artifact package verification after moving every packages/*/dist
• React 19 end-to-end suite: 4 passed
• React 18 end-to-end suite: 1 passed
• all four production example bundles contain no CauseScope instrumentation
• desktop and 390 px mobile documentation visual QA with no browser errors
• repository privacy scan found no credentials, weimob, or fypro references
• independent review completed with no remaining findings

Security note

The complete dependency audit has no high or critical findings. One low advisory remains through tsup -> [email protected]; this repository uses tsup's build API, not esbuild's affected Windows development-server API. Vite 8 is explicitly resolved to patched [email protected].

After merge

• verify the GitHub Pages deployment at https://stackloomdev.github.io/causescope/
• create tag v1.0.0-beta.2; the existing release workflow will re-run the full gate, publish causescope@beta, and create the GitHub prerelease