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/fraction_rule_octave/models.py

@@ -1,4 +1,11 @@
-from sqlalchemy import Integer, String, ForeignKey, PrimaryKeyConstraint, ForeignKeyConstraint, UniqueConstraint
+from sqlalchemy import (
+    Integer,
+    String,
+    ForeignKey,
+    PrimaryKeyConstraint,
+    ForeignKeyConstraint,
+    UniqueConstraint,
+)
 from sqlalchemy.orm import Mapped, mapped_column
 from core.database import Base
 
@@ -6,18 +13,28 @@ from core.database import Base
 class FractionRuleOctave(Base):
     __tablename__ = "fraction_rule_octave"
     __table_args__ = (
-        PrimaryKeyConstraint('id', name='fraction_rule_octave_pkey'),
-        ForeignKeyConstraint(['tenant_id'], ['a76.tenants.id'], name='fk_fraction_rule_octave_tenant'),
-        ForeignKeyConstraint(['company_id'], ['a76.company.id'], name='fk_fraction_rule_octave_company'),
-        UniqueConstraint('tenant_id', 'company_id', 'permission', 'line', 'fraction', name='uq_fraction_rule_octave_permission_line_fraction'),        
-        {"schema": "a76"}
+        PrimaryKeyConstraint("id", name="fraction_rule_octave_pkey"),
+        ForeignKeyConstraint(
+            ["tenant_id"], ["a76.tenants.id"], name="fk_fraction_rule_octave_tenant"
+        ),
+        ForeignKeyConstraint(
+            ["company_id"], ["a76.company.id"], name="fk_fraction_rule_octave_company"
+        ),
+        UniqueConstraint(
+            "tenant_id",
+            "company_id",
+            "permission",
+            "line",
+            "fraction",
+            name="uq_fraction_rule_octave_permission_line_fraction",
+        ),
+        {"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)
-    
+
     permission: Mapped[str] = mapped_column(String(20))
     line: Mapped[int] = mapped_column(Integer)
     fraction: Mapped[str] = mapped_column(String(10))
-