Problem: Right now, each service defines its own error codes or messages independently, which leads to duplication and inconsistency. We want a single, curated list of error codes that can be referenced across all services through our shared sdk.typescript package.
Goal: Create a centralized registry of error codes in sdk.typescript, but is still compatible with the existing sdk gen process.
Add a folder (e.g., api/error-codes/) next to the existing messages/ directory.