fix(deps): bump axios to ^1.16.0 (CVE-2026-44492)

[somesh-banerjee]

Pull Request Description

Bumps axios from ^1.15.2 to ^1.16.0 to address SSRF vulnerability
SNYK-JS-AXIOS-17111062 / CVE-2026-44492.

Affected axios versions: >=1.0.0 <1.16.0. The current SDK dependency
can resolve to 1.15.x, which Snyk flags in consumer CI pipelines.

Fixes #186

Type of change

• Bug fix (non-breaking change which fixes an issue)

How Has This Been Tested?

• Ran npm install and verified npm ls axios resolves to >= 1.16.0
• Locally tested against Fireblocks API (not applicable for dep bump)

Checklist:

• I have performed a self-review of my own code
• I have made corresponding changes to the documentation (N/A)
• Any dependent changes have been merged and published in downstream modules (N/A)