refactor: migrate shared and react-native packages to cordierite scope

[V3RON]

Summary

• rename cordierite-shared to @cordierite/shared
• rename react-native-cordierite to @cordierite/react-native
• keep cordierite unscoped so the CLI package name and executable stay simple

Notes

• this is a hard rename with no compatibility wrapper packages because these packages are not public yet
• workspace folders were renamed to packages/shared and packages/react-native to match the new package identities
• docs, examples, Expo plugin references, playground dependencies, and internal imports were updated to the new scoped names

Verification

• bun install
• bun run build
• bun run test
• bun run lint

Results

• build: passed
• test: passed
• lint: passed with 7 pre-existing no-void warnings in packages/react-native/src/createCordieriteClient.ts, packages/react-native/src/deep-link-core.ts, and packages/react-native/src/deep-link-install.ts