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/service/models.py

@@ -0,0 +1,21 @@
+from datetime import date
+from typing import Literal
+
+from pydantic import BaseModel
+
+
+class Transaction(BaseModel):
+    transaction_id: str
+    date: date
+    account: str
+    amount: float
+    status: Literal["Matched", "Unmatched", "Pending"]
+    flag: Literal["None", "Duplicate", "Threshold Breach", "Manual Review"]
+
+
+class ReconSummary(BaseModel):
+    total: int
+    matched: int
+    unmatched: int
+    pending: int
+    flagged: int