Feature Specification: RBAC & Permissions

1. Overview & Vision

RBAC (Role-Based Access Control) is the platform's governance engine. It ensures that every action taken by a user or service is authorized based on a centralized set of policies, providing organization-level control over sensitive data and features.

2. Personas & Stakeholders

Persona	Goal
Org Admin	Define custom roles and assign permissions to team members.
Member	Perform authorized tasks without encountering security barriers.
System Admin	Define global system roles and monitor policy compliance.

3. User Stories

• As an admin, I want to create a "Finance Manager" role that can view invoices but not change HR records.
• As an admin, I want to temporarily suspend all permissions for a user without deleting their account.

4. Functional Requirements (FR)

• REQ-RBAC-001: Support for custom role definitions per organization.
• REQ-RBAC-002: Centralized permission registry for all satellite apps.
• REQ-RBAC-003: Real-time permission checking via Casbin.
• REQ-RBAC-004: Inherited roles (e.g., admin inherits all member permissions).

5. Non-Functional Requirements (NFR)

• Latency: Permission check < 10ms (cached in Redis).
• Auditability: Every permission change MUST be logged in the audit trail.

6. Business Logic & Rules

• Subject-Object-Action (SOA): Policies follow the Casbin model: p, sub, obj, act.
• Default Roles: Every new organization is provisioned with Owner, Admin, and Member.
• Scope: Permissions can be scoped to a specific satellite module (e.g., drive:*).

7. User Interface (UI/UX)

• "Roles & Permissions" editor with a matrix-style checkbox grid.
• User-to-Role assignment interface with bulk management.
• Visual indicators for inherited vs. explicitly granted permissions.

8. Information Architecture

• Located under "Organization Settings" in the Shell.
• Grouped by satellite module for clarity.

9. Data Model & Persistence

• Tables: roles, permissions, role_permissions, user_roles.
• Engine: Casbin with PostgreSQL adapter.

10. API & Service Layer

• GET /api/roles
• POST /api/roles/:id/permissions
• RbacService.CheckPermission (gRPC)

11. Integration Patterns

• Satellite apps perform remote permission checks via the Shell gRPC gateway.
• Declarative @authorize() decorators in satellite controllers.

12. Security & Permissions

• Only Owner or Admin can modify roles.
• Cross-tenant role assignment is strictly prohibited.

13. Error Handling & Resilience

• Graceful 403 Forbidden responses with a description of the missing permission.
• Fallback to "Deny All" if the Casbin engine fails.

14. Performance & Scalability

• Enforcer policies are cached in Redis for fast evaluation.
• Local policy caching in satellite modules (planned for v1.2).

15. Globalization & i18n

• Permission names and descriptions are localized (EN/VI).

16. Accessibility (a11y)

• Accessible permission grid (keyboard navigation, high contrast).

17. Observability & Analytics

• Tracking of "Denied Actions" to identify potential security threats or UX friction.

18. Testing & Quality

• Policy unit tests to ensure Admin always has full access.
• Negative tests to verify data isolation.

19. Constraints & Assumptions

• Assumes satellite apps correctly define their own permission codes in the Shell registry.

20. Future Enhancements

• Resource-based permissions (e.g., "Access only to Folder X").
• Time-bound role assignments (temporary permissions).