feat: Implement multi-tenancy support in middleware and security layers

- Enhanced TenantMiddleware to validate tenant information from JWT tokens.
- Added LicenseValidationMiddleware to check tenant licenses before processing requests.
- Updated security utilities to extract tenant information from tokens and validate company access.
- Introduced CompanyStore to manage active company state and handle company switching in the frontend.
- Modified API routes to include company_id in requests for better resource management.
- Improved logging and error handling throughout the middleware and API layers.
- Updated frontend components to reflect changes in company management and selection.
- Added new API route for fetching user's companies with proper authentication handling.

backend/api/v1/modules/a76/exchange_rate/models.py

@@ -1,6 +1,15 @@
 from typing import Optional
 from decimal import Decimal
-from sqlalchemy import Integer, String, DECIMAL, PrimaryKeyConstraint, DateTime, ForeignKeyConstraint, UniqueConstraint, ForeignKey
+from sqlalchemy import (
+    Integer,
+    String,
+    DECIMAL,
+    PrimaryKeyConstraint,
+    DateTime,
+    ForeignKeyConstraint,
+    UniqueConstraint,
+    ForeignKey,
+)
 from sqlalchemy.orm import Mapped, mapped_column
 from core.database import Base
 
@@ -8,18 +17,24 @@ from core.database import Base
 class ExchangeRate(Base):
     __tablename__ = "exchange_rate"
     __table_args__ = (
-        PrimaryKeyConstraint('id', name='exchange_rate_pkey'),
-        ForeignKeyConstraint(['tenant_id'], ['a76.tenants.id'], name='fk_exchange_rate_tenant'),
-        ForeignKeyConstraint(['company_id'], ['a76.company.id'], name='fk_exchange_rate_company'),
-        UniqueConstraint('tenant_id', 'company_id', 'date', name='uq_exchange_rate_date_tenant'),
-        {"schema": "a76"}
+        PrimaryKeyConstraint("id", name="exchange_rate_pkey"),
+        ForeignKeyConstraint(
+            ["tenant_id"], ["a76.tenants.id"], name="fk_exchange_rate_tenant"
+        ),
+        ForeignKeyConstraint(
+            ["company_id"], ["a76.company.id"], name="fk_exchange_rate_company"
+        ),
+        UniqueConstraint(
+            "tenant_id", "company_id", "date", name="uq_exchange_rate_date_tenant"
+        ),
+        {"schema": "a76"},
     )
 
     id: Mapped[int] = mapped_column(Integer, primary_key=True)
     tenant_id: Mapped[int] = mapped_column(Integer, nullable=False, index=True)
     company_id: Mapped[int] = mapped_column(Integer, nullable=False, index=True)
-    
+
     date: Mapped[int] = mapped_column(DateTime)
     value: Mapped[Optional[Decimal]] = mapped_column(DECIMAL(13, 6))
     local_currency: Mapped[Optional[str]] = mapped_column(String(7))
-    foreign_currency: Mapped[Optional[str]] = mapped_column(String(7))        
+    foreign_currency: Mapped[Optional[str]] = mapped_column(String(7))