feat: shareable permalink for a simulated call

[Hollujay]

Summary

A simulation is currently ephemeral. If you find surprising behaviour and want
to show someone, you have to describe the contract address, function, and every
argument by hand.

Acceptance Criteria

• Encode contract address, selected function, arguments, and network into
  the URL
• Loading such a URL restores the form ready to simulate (do not
  auto-simulate on load — that would fire network calls from a pasted link)
• Add a "copy link" affordance once a simulation has run
• Handle malformed or truncated URLs gracefully rather than crashing

Tech Stack

TypeScript, React