remove `uint8ArrayToHex` and `hexToUint8Array` from our lib

[gudnuf]

We now have the @noble library installed which has equivalent utilities and are more robustly implemented. We should remove our utility functions uint8ArrayToHex and hexToUint8Array and prefer usage of bytesToHex and hexToBytes from @noble/hashes.

[jbojcic1]

@claude can you do this?

[claude]

Claude finished @jbojcic1's task in 1m 3s —— View job • claude/issue-626-20260304-1121 • Create PR ➔

---

Replacing uint8ArrayToHex / hexToUint8Array with @noble/hashes utilities

• Find all usages of uint8ArrayToHex and hexToUint8Array
• Replace with bytesToHex / hexToBytes from @noble/hashes
• Remove old utility functions from app/lib/utils.ts
• Run fix:all — no errors

Changes:

• app/features/shared/encryption.ts — replaced 3 calls to hexToUint8Array with hexToBytes from @noble/hashes/utils
• app/lib/utils.ts — removed both hexToUint8Array and uint8ArrayToHex (the latter had zero usages)

uint8ArrayToHex was unused, but its @noble/hashes equivalent (bytesToHex) is already used in app/lib/spark/utils.ts.