Rename keyring to keyAuth throughout go backend

[coderabbitai]

Problem

There's an inconsistency in naming conventions throughout the go backend where some places use 'keyring' and others use 'keyAuth'. This creates confusion and makes the code harder to maintain.

Example: In go/pkg/db/queries/key_insert.sql, the SQL column is named key_auth_id but the sqlc argument is keyring_id.

Task

Rename all instances of 'keyring' to 'keyAuth' throughout the go backend for consistency. This includes:

• Variable names
• Function parameters
• SQL query arguments
• Type names
• Database queries and related code

Context

This issue was identified during code review of PR #3841.

Backlinks:

• PR: feat: poc migrating from prefixed-api-key #3841
• Comment: feat: poc migrating from prefixed-api-key #3841 (comment)

Requested by: @Flo4604

[linear]

ENG-2027 Rename keyring to keyAuth throughout go backend