fix: remove hardcoded trailing question mark from user query

[feelbadinc]

Description

Took out the hardcoded question mark that was being added to user queries in BaseModel prepare() method. Not sure whether that was intentional, but it definitely feels off - especially when the query wasn't even a question to start with.

This was discovered independently and doesn't relate to any opened issues.

Type of change

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

How Has This Been Tested?

I verified that user queries are now always passed to the model exactly as-is. No thorough testing required, since it's quite a simple and safe fix.

Checklist:

• [✅] My code follows the style guidelines of this project
• [✅] I have performed a self-review of my own code
• [❌] I have commented my code, particularly in hard-to-understand areas - not applicable
• [❌] I have made corresponding changes to the documentation - not applicable
• [✅] My changes generate no new tsc or eslint warnings
• [✅] I have ran tests that prove my fix is effective or that my feature works
• [❌] Any dependent changes have been merged and published in downstream modules - not applicable
• [✅] I have checked my code and corrected any misspellings
• [✅] My changes do not result in new npm audit errors