Make internal logging configurable

[necipsagiro]

Summary

The SDK writes directly to console.log / console.warn from several internal code paths. When embedded in a Node service that uses a structured logger (pino, winston, etc.), these unstructured lines pollute stdout and break log ingestion. There's currently no way to disable them without monkey-patching console.

Example output per attestation

sendTransaction params: submitTask 0x52ca...  1 0 0x0000... { value: BigNumber {...}, ... }
findFastestWs [ '...phala.network' ]
testSpeed done [ '...phala.network' ]
----------Attest algorithm duration: 30514
attestationList from algorithm [ { attestation: {...}, signature: '0x...', ... } ]

The attestationList line is particularly heavy since it includes the full signed attestation on every call.

A few of the call sites (there are more): src/index.ts#L391, src/classes/Contract.ts#L43, src/utils.ts#L158.

Proposed fix

Option 1: silent flag

Add a silent option on the constructor:

const primus = new PrimusZKTLS({ silent: true });

• Defaults to false, so current behavior is preserved.
• When true, all internal console.log / console.warn / console.error calls become no-ops.

Option 2: optional logger

Accept an optional logger on the constructor that conforms to a small interface and route all internal logs through it:

interface Logger {
  info(...args: unknown[]): void;
  warn(...args: unknown[]): void;
  error(...args: unknown[]): void;
}

const primus = new PrimusZKTLS({ logger: pino() });

• Defaults to console, so current behavior is preserved.
• Covers the "I want to keep the diagnostic output but in structured form" case that Option 1 intentionally does not.

Happy to open a PR for whichever direction you prefer.