Add dev runtime platform config API

[techmannih]

Summary

Adds a CLI dev-server runtime config bridge so tscircuit.config.ts can participate in dev preview without sending raw function-valued config or secrets to the browser.

What changed

• Adds /api/dev/runtime-config for browser-safe runtime platform config payloads.
• Adds /api/dev/runtime-config/rpc so function-valued platformConfig fields execute on the CLI server.
• Injects window.TSCIRCUIT_RUNTIME_CONFIG_API_URL into the dev HTML shell.
• Loads runtime project config in DevServer.start() so dev can use tscircuit.config.ts for config like ignored files.
• Covers the secret-safe RPC flow with a focused dev-server test.

Validation

• bun test tests/cli/dev/runtime-config-api.test.ts tests/lib/project-config.test.ts
• bunx tsc --noEmit --pretty false