fix(playground): validate and restore every demo

[doodlewind]

Summary

• restore Octane compiler/runtime linking, audio subpaths, Cursor setup, and Launcher registry/assets
• route the split Vue Vapor runtime and JSX text helpers through the PocketJS native document facade
• audit every generated Playground module against the emitted browser bundles during site builds
• require attached host text, valid native node IDs, clean runtime state, and deterministic input changes across all 12 demos and 28 framework variants

Validation

• bun run site:build
• bun site/verify-playground.ts (28/28 variants)
• bun run test (11/11 stages; 373 primary unit tests)
• bun test tests/iphone2g-device-transaction.test.ts (6/6)
• bunx tsc --noEmit
• git diff --check