feat: add proxy connect provider

[thymikee]

Summary

Add agent-device connect proxy --daemon-base-url ... as a normal remote connection provider.

This keeps proxy connection state in RemoteConnectionState, generates non-secret remote config profiles, acquires a device-aware proxy lease before open side effects, and propagates provider/client/device lease metadata through the existing client and daemon lease contracts.

Plan 001 overlap is kept to the canonical open-ended lease model: leaseProvider?: string, legacy provider compatibility, and general DeviceLease device binding.

Related PR Context

This PR is the Worker B / Plan 002 slice only. It depends on Plan 001’s canonical DeviceLease model and is completed by Plan 003’s daemon session admission/expiry cleanup plus Plan 004/#888 runner diagnostics/docs.

The integrated reconciled stack is now in #890. Review #890 for the end-to-end behavior and use this PR as the isolated connect proxy implementation slice if reviewing changes independently.

Validation

• pnpm format
• pnpm exec vitest run src/__tests__/remote-connection.test.ts src/__tests__/cloud-connect-profile.test.ts src/utils/__tests__/args.test.ts
• pnpm exec vitest run src/daemon/__tests__/request-router-open.test.ts
• node --test test/integration/smoke-open-remote-config.test.ts
• pnpm typecheck
• pnpm exec vitest run src/__tests__/remote-connection.test.ts src/__tests__/cloud-connect-profile.test.ts src/utils/__tests__/args.test.ts src/daemon/__tests__/request-router-open.test.ts

[thymikee]

Coordinator update: this PR is the isolated connect-proxy provider slice. The reconciled end-to-end leasing stack is now in #890, which folds this work together with the canonical lease model, daemon session admission/expiry cleanup, and runner diagnostics/docs. Review #890 for integrated behavior; keep this PR for focused proxy-provider review if needed.

[thymikee]

Closing as superseded by #890, which integrates the lease contract, proxy connect, session admission/expiry, and diagnostics work. Please continue review there.