Centralize config through Settings singleton

UPLOAD_DIR and DB_PATH were read directly from os.environ, bypassing
the Settings dataclass. This caused an inconsistency where overriding
Settings had no effect on these values. Now all modules import from
infra.settings.settings.

document-parser/infra/settings.py

@@ -21,6 +21,7 @@ class Settings:
 
     @classmethod
     def from_env(cls) -> Settings:
+        """Build a Settings instance from environment variables."""
         cors_raw = os.environ.get("CORS_ORIGINS", "http://localhost:3000,http://localhost:5173")
         return cls(
             app_version=os.environ.get("APP_VERSION", "dev"),
@@ -32,3 +33,7 @@ class Settings:
             db_path=os.environ.get("DB_PATH", "./data/docling_studio.db"),
             cors_origins=[o.strip() for o in cors_raw.split(",")],
         )
+
+
+# Module-level singleton — import this from other modules.
+settings = Settings.from_env()

document-parser/main.py

@@ -19,7 +19,7 @@ from fastapi.middleware.cors import CORSMiddleware
 
 from api.analyses import router as analyses_router
 from api.documents import router as documents_router
-from infra.settings import Settings
+from infra.settings import settings
 from persistence.database import init_db
 from services.analysis_service import AnalysisService
 
@@ -29,12 +29,6 @@ logging.basicConfig(
 )
 logger = logging.getLogger(__name__)
 
-# ---------------------------------------------------------------------------
-# Settings & dependency wiring
-# ---------------------------------------------------------------------------
-
-settings = Settings.from_env()
-
 
 def _build_converter():
     """Build the converter adapter based on configuration."""

document-parser/persistence/database.py

@@ -8,9 +8,11 @@ from contextlib import asynccontextmanager
 
 import aiosqlite
 
+from infra.settings import settings
+
 logger = logging.getLogger(__name__)
 
-DB_PATH = os.environ.get("DB_PATH", "./data/docling_studio.db")
+DB_PATH = settings.db_path
 
 _SCHEMA = """
 CREATE TABLE IF NOT EXISTS documents (

document-parser/services/document_service.py

@@ -10,11 +10,12 @@ import uuid
 from pdf2image import convert_from_bytes, pdfinfo_from_bytes
 
 from domain.models import Document
+from infra.settings import settings
 from persistence import analysis_repo, document_repo
 
 logger = logging.getLogger(__name__)
 
-UPLOAD_DIR = os.environ.get("UPLOAD_DIR", "./uploads")
+UPLOAD_DIR = settings.upload_dir
 MAX_FILE_SIZE = 50 * 1024 * 1024  # 50 MB
 
 

document-parser/tests/test_settings.py

@@ -0,0 +1,75 @@
+"""Tests for Settings — environment variable parsing and defaults."""
+
+from __future__ import annotations
+
+from infra.settings import Settings
+
+
+class TestSettingsDefaults:
+    def test_default_values(self):
+        s = Settings()
+        assert s.app_version == "dev"
+        assert s.conversion_engine == "local"
+        assert s.docling_serve_url == "http://localhost:5001"
+        assert s.docling_serve_api_key is None
+        assert s.conversion_timeout == 600
+        assert s.upload_dir == "./uploads"
+        assert s.db_path == "./data/docling_studio.db"
+        assert "http://localhost:3000" in s.cors_origins
+
+    def test_frozen(self):
+        """Settings should be immutable."""
+        import pytest
+
+        s = Settings()
+        with pytest.raises(AttributeError):
+            s.upload_dir = "/other"  # type: ignore[misc]
+
+
+class TestSettingsFromEnv:
+    def test_reads_env_vars(self, monkeypatch):
+        monkeypatch.setenv("APP_VERSION", "1.2.3")
+        monkeypatch.setenv("CONVERSION_ENGINE", "remote")
+        monkeypatch.setenv("DOCLING_SERVE_URL", "http://serve:9000")
+        monkeypatch.setenv("DOCLING_SERVE_API_KEY", "secret-key")
+        monkeypatch.setenv("CONVERSION_TIMEOUT", "120")
+        monkeypatch.setenv("UPLOAD_DIR", "/data/uploads")
+        monkeypatch.setenv("DB_PATH", "/data/test.db")
+        monkeypatch.setenv("CORS_ORIGINS", "http://a.com, http://b.com")
+
+        s = Settings.from_env()
+
+        assert s.app_version == "1.2.3"
+        assert s.conversion_engine == "remote"
+        assert s.docling_serve_url == "http://serve:9000"
+        assert s.docling_serve_api_key == "secret-key"
+        assert s.conversion_timeout == 120
+        assert s.upload_dir == "/data/uploads"
+        assert s.db_path == "/data/test.db"
+        assert s.cors_origins == ["http://a.com", "http://b.com"]
+
+    def test_defaults_when_env_empty(self, monkeypatch):
+        """When no env vars set, from_env returns sensible defaults."""
+        for key in (
+            "APP_VERSION",
+            "CONVERSION_ENGINE",
+            "DOCLING_SERVE_URL",
+            "DOCLING_SERVE_API_KEY",
+            "CONVERSION_TIMEOUT",
+            "UPLOAD_DIR",
+            "DB_PATH",
+            "CORS_ORIGINS",
+        ):
+            monkeypatch.delenv(key, raising=False)
+
+        s = Settings.from_env()
+
+        assert s.app_version == "dev"
+        assert s.conversion_engine == "local"
+        assert s.conversion_timeout == 600
+
+    def test_cors_origins_split(self, monkeypatch):
+        monkeypatch.setenv("CORS_ORIGINS", "http://a.com,http://b.com,http://c.com")
+        s = Settings.from_env()
+        assert len(s.cors_origins) == 3
+        assert s.cors_origins[2] == "http://c.com"