test(transport): cover ServerMetadataStore lifecycle

[1amKhush]

Problem

ServerMetadataStore owns client-side discovery metadata and negotiated feature state, but it does not have a focused unit test suite. Its clear() behavior and parsing fallbacks are especially important when a transport is reused or reconnects.

Scope

Add src/transport/nostr-client/server-metadata-store.test.ts covering the existing behavior:

• initialize-event storage and retrieval;
• valid and invalid InitializeResult parsing;
• tool, resource, resource-template, and prompt list envelope storage;
• oversized-transfer and open-stream support flags;
• effective payment-interaction state;
• name, about, website, picture, and encryption tags;
• clear() resetting every stored event, flag, and negotiated value.

Reuse existing Nostr event fixtures or add a small local fixture builder in the test file.

Non-goals

• Do not change transport lifecycle or protocol negotiation behavior.
• Do not add new metadata fields.
• Keep production changes out of scope unless a test exposes a confirmed defect.

Acceptance criteria

• Tests cover both populated and empty/default store state.
• Tests are deterministic and make no relay or network calls.
• Existing tests, lint, and type checking continue to pass.

Verification

bun test src/transport/nostr-client/server-metadata-store.test.ts
bun lint
bun typecheck