cli: validate addresses before send and fund

[jovial-liu]

Adds early validation to the creator CLI so invalid addresses fail fast instead of making network requests.

This covers:

• automaton-cli send
• automaton-cli fund
• relay URL validation in send
• a small CLI test file for invalid address handling

Validated with pnpm install, pnpm typecheck, pnpm build, and pnpm test src/__tests__/cli-commands.test.ts.

I also tried pnpm test -- cli-commands, but that surfaced unrelated existing failures in the repo.

[jovial-liu]

Hi maintainers, could someone take a look at this small CLI validation PR?

I re-checked it against current main and it is still cleanly mergeable.

Validation passed:

• npm run typecheck
• npm test src/__tests__/cli-commands.test.ts
• npx pnpm@10.28.1 build

This prevents invalid recipient/destination addresses from reaching network calls in send and fund.