Feature: Multi-Workspace Tenancy with RBAC and Isolated Knowledge Bases

Summary

Add first-class multi-workspace support so one deployment can safely serve multiple portfolio teams with strict data isolation, RBAC, and workspace-scoped retrieval/session state.

Why this matters

The current platform behaves like a single-tenant system. For real adoption across multiple investor teams, we need tenant boundaries so data, sessions, and retrieval context never leak between workspaces.

Scope

• Workspace model (workspace, membership, role).
• Role-based access control (owner, editor, viewer) for API and frontend actions.
• Workspace-scoped data isolation for:
  • chat sessions
  • vector indexes / collections
  • cached responses
  • ingestion jobs
• Workspace context propagation through request lifecycle and backend tool calls.
• Audit trail for high-risk actions (ingest, delete, reindex, export).

Non-goals

• Full enterprise SSO implementation in this issue (can be follow-up).
• Billing/plan management.

Proposed implementation

1. Introduce workspace entities in backend (Mongo) and auth middleware that resolves workspace_id + role.
2. Enforce workspace filters in all backend routes and RAG service storage layers.
3. Partition vector stores by workspace namespace/collection.
4. Add workspace switcher in frontend and block cross-workspace session loading.
5. Add request-level policy checks and structured audit logs.

Acceptance criteria

• Users can belong to multiple workspaces and switch context in UI.
• Every chat, retrieval, and ingestion request is bound to one workspace.
• Cross-workspace reads/writes are blocked at API and storage layers.
• Role restrictions are enforced for ingestion, deletion, and admin operations.
• Automated tests cover authorization matrix and isolation guarantees.
• Audit events are emitted with actor, workspace, action, and target.

Dependencies / sequencing

• Should align with API modularization work but is not blocked on full FastAPI migration.

Labels

enhancement, security, backend, frontend