fix: allow zero seed in optimization configurations

docs/optimizer_config.schema.json

@@ -1242,7 +1242,7 @@
         },
         "seed": {
             "default": 42,
-            "exclusiveMinimum": 0,
+            "minimum": 0,
             "title": "Seed",
             "type": "integer"
         }

src/autointent/_optimization_config.py

@@ -2,7 +2,7 @@
 
 from typing import TYPE_CHECKING, Any
 
-from pydantic import BaseModel, Field, PositiveInt, field_validator
+from pydantic import BaseModel, Field, NonNegativeInt, field_validator
 
 from .configs import (
     CrossEncoderConfig,
@@ -49,7 +49,7 @@ def validate_embedder_config(cls, v: Any) -> EmbedderConfig:  # noqa: ANN401
 
     hpo_config: HPOConfig = HPOConfig()
 
-    seed: PositiveInt = 42
+    seed: NonNegativeInt = 42
 
     @classmethod
     def from_preset(cls, preset: SearchSpacePreset) -> OptimizationConfig:

tests/configs/test_full_config.py

@@ -1,7 +1,7 @@
 import pytest
 from pydantic import ValidationError
 
-from autointent import OptimizationConfig
+from autointent import OptimizationConfig, Pipeline
 from tests.conftest import load_optimization_config
 
 
@@ -17,3 +17,26 @@ def test_not_valid_reporting() -> None:
 
     with pytest.raises(ValidationError):
         OptimizationConfig(**config)
+
+
+@pytest.mark.parametrize("seed", [0, 42])
+def test_non_negative_seed(seed: int) -> None:
+    config = OptimizationConfig(seed=seed, search_space=[])
+    assert config.seed == seed
+
+
+def test_negative_seed_is_rejected() -> None:
+    with pytest.raises(ValidationError, match="seed"):
+        OptimizationConfig(seed=-1, search_space=[])
+
+
+def test_pipeline_from_preset_accepts_zero_seed() -> None:
+    pipeline = Pipeline.from_preset("classic-light", seed=0)
+    assert pipeline._seed == 0
+
+
+def test_pipeline_from_optimization_config_accepts_zero_seed() -> None:
+    config = load_optimization_config("full_training")
+    config["seed"] = 0
+    pipeline = Pipeline.from_optimization_config(config)
+    assert pipeline._seed == 0