chore: Add explanatory comment to QueryDeepPartialEntity import

[GitAddRemote]

Description

Add a comment to the QueryDeepPartialEntity import in base-uex.repository.ts to explain why we're using a deep import from TypeORM's internal path.

Location

backend/src/modules/uex/repositories/base-uex.repository.ts:7

Current Code

import { QueryDeepPartialEntity } from 'typeorm/query-builder/QueryPartialEntity';

Suggested Enhancement

// TypeORM doesn't export QueryDeepPartialEntity from main package
// This is a stable internal API used by Repository.update() signature
import { QueryDeepPartialEntity } from 'typeorm/query-builder/QueryPartialEntity';

Rationale

• Clarifies why we're using an internal import path
• Helps future developers understand this is intentional
• Documents that this is a stable TypeORM API (not a hack)
• Useful if TypeORM changes internal structure in future versions

Priority

Low - This is a documentation improvement, not a functional issue.

Related

Part of code review follow-up from #100