fix: Improve logging when not initialized

[roncohen]

Correctly initializing the BucketClient can be a bit tricky. This should complain more loudly when it happens.

I considered and rejected the idea of throwing an error when this happens because incorrectly constructed initialization code may only break under high concurrency and thus only show up in production which could cause down time if we throw.

[Copilot]

Pull Request Overview

This PR enhances client initialization logging and error messages without throwing exceptions, by tracking initialization state and improving diagnostics.

• Track initialization completion and log an error if methods are used before init
• Include offline mode context in the "Bucket initialized" info log
• Refine secretKey validation message and update tests to reflect new warn text

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
packages/node-sdk/test/client.test.ts	Updated expected warning string to match code change
packages/node-sdk/src/client.ts	Added initializationFinished flag, enhanced logs, and refined error messages

Comments suppressed due to low confidence (2)

packages/node-sdk/src/client.ts:130

• [nitpick] Consider renaming initializationFinished to isInitialized to make it clear this is a boolean flag.

private initializationFinished = false;

packages/node-sdk/src/client.ts:967

• There's no unit test covering the branch where getFeature(s) is called before initialization—add a test to verify the error log.

if (!this.initializationFinished) {