Release installable Seda 0.3.0 packages

[pnegahdar]

Summary

• version the unreleased exact-model and SDK work as Seda 0.3.0
• make the universal client a peer of the browser and Node packages so GitHub tarballs install without npm
• add a clean packed-package install/import regression check with exotic subdependencies blocked

Verification

• cargo check --offline --workspace
• cargo build --locked -p seda-cli --features test-engine
• pnpm check
• pnpm test
• pnpm build
• pnpm check:package-install