Low-Level Category Filter APIs Bypass Schema Enforcement

[shaleenji]

Description

add_to_filter() and related low-level category APIs can write category data without registering or checking the filter schema. This can create category entries for fields later typed as numeric or boolean.

Steps to Reproduce

1. Call add_to_filter("score", "10", id) directly.
2. Insert JSON filter { "score": 10 }.
3. Query both category-style and numeric-style filters for score.

Expected Behavior

All filter writes should honor the same first-write-wins schema/type rules.

Actual Behavior

Low-level category writes can bypass schema registration and type checks.