refactor(cli): migrate registry to TypeScript

[cv]

Summary

Migrate the sandbox registry implementation from bin/lib/registry.js to src/lib/registry.ts, keeping the existing API surface and replacing the JS file with a shim to the compiled implementation.

Why

This is the next core-substrate step after #1552:

• move central CLI state management into typed code
• keep the strangler pattern already used across the repo
• unblock later credentials / policies cleanup and TS backedge removal

Changes

• add src/lib/registry.ts
• replace bin/lib/registry.js with a thin shim to dist/lib/registry
• route registry persistence through the new config-io substrate
• update the write-failure test to accept the new user-facing config write error

Testing

• npm run build:cli
• npx vitest run test/registry.test.js
• npx vitest run test/cli.test.js test/registry.test.js

Stack

Depends on #1552 (refactor(cli): add config-io module). Once that merges, this PR can be retargeted to main.

Relates to #924.