fix(gql): render boolean where-filter lists as lowercase GraphQL literals

[linhongyu510]

What

Boolean where-filter lists were rendered into the aggregate GraphQL query with Python's str(), emitting capitalized True/False. Those are not valid GraphQL boolean literals, so a where filter containing a boolean list produced a query the server rejects at parse time.

The single-boolean path already rendered correctly via _bool_to_str() (true/false); only the list path was wrong — an asymmetry between the two branches.

Reproduction

Building an aggregate query with a boolean list filter (reachable through the public Filter DSL):

from weaviate.collections.classes.filters import Filter
from weaviate.collections.filters import _FilterToREST
from weaviate.gql.aggregate import AggregateBuilder

b = AggregateBuilder("Question")
b.with_where(_FilterToREST.convert(Filter.by_property("active").contains_any([True, False]))).with_meta_count()
print(b.build())

Before:

{Aggregate{Question(where: {path: ["active"] operator: ContainsAny valueBoolean: [True,False]} ){meta{count}}}}

([True,False] is invalid GraphQL — the server fails to parse the query.)

After:

{Aggregate{Question(where: {path: ["active"] operator: ContainsAny valueBoolean: [true,false]} ){meta{count}}}}

Root cause

In Where.__str__ (weaviate/gql/filter.py), the boolean branch used _render_list(self.value) for list values, which joins with str(item). str(True) is "True". The non-list branch correctly used _bool_to_str. The fix maps _bool_to_str over each list element, matching the single-value branch.

This affects valueBooleanArray / valueBooleanList (e.g. Filter.by_property(...).contains_any([...]) / contains_all([...]) with booleans) in aggregate queries built by AggregateBuilder.

Tests

Added test/test_where_filter.py (pure unit tests, no live server):

• boolean list renders as lowercase [true,false,true] and contains no True/False (regression — fails on the old code)
• single boolean rendering is unchanged
• string/int list rendering is unchanged

Existing test/collection/test_filter.py and test/test_util.py continue to pass.

[orca-security-eu]

Orca Security Scan Summary

Status	Check	Issues by priority
Passed	Infrastructure as Code	0   0   0   0	View in Orca
Passed	SAST	0   0   0   0	View in Orca
Passed	Secrets	0   0   0   0	View in Orca
Passed	Vulnerabilities	0   0   0   0	View in Orca

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[linhongyu510]

I agree to the Weaviate Contributor License Agreement.

Transparency note: this change was prepared with AI assistance (bug localization, patch drafting, and regression tests). I have reviewed the final diff line by line against the existing code paths — the single-boolean branch already rendered lowercase via _bool_to_str(); this only applies the same lowercasing to list elements — and verified the before/after GraphQL output locally. No other call sites or list types (string/int/date) were changed.