feat(api): node.dial should accept httpi:// URLs, not just bare public keys

[momics]

Summary

node.dial(peer) currently accepts a PublicKey instance or a base32 public-key string. Extend it to also accept a full httpi:// URL and extract the public key from the hostname — matching what node.fetch() already does.

Evidence

IrohNode.dial() calls resolveNodeId(peer) which only handles the PublicKey | string union (packages/iroh-http-shared/src/PublicKey.ts#L139-L142). A user passing node.dial("httpi://tvtswinq.../something") will get an invalid base32 string error from the Rust side because the whole URL is forwarded as a node-id. Meanwhile node.fetch(input) accepts httpi:// URLs natively via new URL(raw); nodeId = parsed.hostname; (packages/iroh-http-shared/src/fetch.ts#L48-L60).

Impact

Inconsistent UX between fetch and dial. Users who already have an httpi:// URL (e.g. the peer.toURL() return value, or a copy-pasted address) currently have to strip the scheme manually before calling dial.

Remediation

Extend resolveNodeId(peer: PublicKey | string) (or add a sibling helper used by dial) to:

1. If the string starts with httpi:// (case-insensitive), parse via WHATWG URL and use .hostname.
2. Otherwise treat as a bare base32 string (existing behaviour).
3. Reject http:// / https:// with a clear error (mirror the rejection in fetch.ts).

Apply to dial() and any other call site that takes a peer identity string.

Acceptance criteria

• node.dial("httpi://<base32-key>") works end-to-end.
• node.dial("httpi://<base32-key>/some/path") works (path ignored — dial opens a session, not a request).
• node.dial(peer.toURL()) works (interop with PublicKey.toURL()).
• node.dial("https://example.com") throws a clear error.
• node.dial(<bare-base32>) continues to work (no regression).
• Test added to tests/suites/sessions.mjs covering all four cases.