feat: Initialize FastAPI application with Azure authentication and transaction management

- Added .env.example for environment variable configuration.
- Created app initialization files and core settings management.
- Implemented API routers for reporting and transaction endpoints.
- Developed transaction management service with CRUD operations.
- Integrated Azure OAuth for user authentication.
- Designed dashboard view with transaction filtering and display.
- Added Swagger UI documentation with custom dark theme.
- Created static and template files for frontend styling and layout.

app/core/__init__.py

@@ -0,0 +1,3 @@
+from app.core.app_factory import create_app
+
+__all__ = ["create_app"]

app/core/app_factory.py

@@ -0,0 +1,40 @@
+from pathlib import Path
+
+from fastapi import FastAPI
+from starlette.middleware.sessions import SessionMiddleware
+from fastapi.staticfiles import StaticFiles
+
+from app.api.reporting import router as reporting_router
+from app.api.transactions import router as transactions_router
+from app.core.settings import get_settings
+from app.views.auth import router as auth_router
+from app.views.dashboard import router as dashboard_router
+from app.views.docs import router as docs_router
+
+
+def create_app() -> FastAPI:
+    settings = get_settings()
+
+    app = FastAPI(
+        title="Recon Ranger",
+        description="Financial crime reconciliation API — patrol your data landscape for inconsistencies.",
+        version="0.1.0",
+        docs_url=None,
+    )
+    app.add_middleware(
+        SessionMiddleware,
+        secret_key=settings.session_secret_key,
+        same_site="lax",
+        https_only=False,
+    )
+
+    project_root = Path(__file__).resolve().parents[2]
+    static_dir = project_root / "data" / "static"
+    app.mount("/static", StaticFiles(directory=str(static_dir)), name="static")
+
+    app.include_router(transactions_router)
+    app.include_router(reporting_router)
+    app.include_router(auth_router)
+    app.include_router(dashboard_router)
+    app.include_router(docs_router)
+    return app

app/core/auth.py

@@ -0,0 +1,22 @@
+from functools import lru_cache
+
+from authlib.integrations.starlette_client import OAuth
+
+from app.core.settings import get_settings
+
+
+@lru_cache
+def get_oauth() -> OAuth:
+    settings = get_settings()
+    oauth = OAuth()
+    oauth.register(
+        name="azure",
+        client_id=settings.azure_client_id,
+        client_secret=settings.azure_client_secret,
+        server_metadata_url=(
+            f"https://login.microsoftonline.com/{settings.azure_tenant_id}"
+            "/v2.0/.well-known/openid-configuration"
+        ),
+        client_kwargs={"scope": "openid profile email"},
+    )
+    return oauth

app/core/settings.py

@@ -0,0 +1,26 @@
+from functools import lru_cache
+from os import getenv
+from pathlib import Path
+
+from dotenv import load_dotenv
+
+
+PROJECT_ROOT = Path(__file__).resolve().parents[2]
+load_dotenv(PROJECT_ROOT / ".env")
+
+
+class Settings:
+    def __init__(self) -> None:
+        self.session_secret_key = getenv("SESSION_SECRET_KEY", "change-me-in-production")
+        self.azure_tenant_id = getenv("AZURE_TENANT_ID")
+        self.azure_client_id = getenv("AZURE_CLIENT_ID")
+        self.azure_client_secret = getenv("AZURE_CLIENT_SECRET")
+
+    @property
+    def azure_configured(self) -> bool:
+        return bool(self.azure_tenant_id and self.azure_client_id and self.azure_client_secret)
+
+
+@lru_cache
+def get_settings() -> Settings:
+    return Settings()