refactoring: add initial pipeline configuration and model classes

core/config/project_paths.py

@@ -0,0 +1,23 @@
+from pathlib import Path
+
+from pydantic import BaseModel, field_validator
+
+
+class ProjectPaths(BaseModel):
+    """Project directory structure configuration"""
+
+    root_dir: Path
+    data_dir: Path
+    models_dir: Path
+    outputs_dir: Path
+    logs_dir: Path
+    configs_dir: Path
+    checkpoints_dir: Path
+
+    class Config:
+        arbitrary_types_allowed = True
+
+    @classmethod
+    @field_validator("*", mode="before")
+    def convert_to_path(cls, v):
+        return Path(v) if not isinstance(v, Path) else v