feat: enforce tenant isolation for audit logs and enhance user list filtering for multi-tenant admins

backend/internal/handler/audit_handler.go

@@ -58,6 +58,8 @@ func (h *AuditHandler) CreateLog(c *fiber.Ctx) error {
 func (h *AuditHandler) ListLogs(c *fiber.Ctx) error {
 	limit := c.QueryInt("limit", 50)
 	cursorRaw := c.Query("cursor")
+	requestedTenantID := c.Query("tenantId")
+
 	cursor, err := parseAuditCursor(cursorRaw)
 	if err != nil {
 		return errorJSON(c, fiber.StatusBadRequest, "Invalid cursor")
@@ -67,7 +69,41 @@ func (h *AuditHandler) ListLogs(c *fiber.Ctx) error {
 		return errorJSON(c, fiber.StatusServiceUnavailable, "Audit service unavailable")
 	}
 
-	logs, err := h.repo.FindPage(c.Context(), limit+1, cursor)
+	// [New] Role-based Filtering
+	profile, _ := c.Locals("user_profile").(*domain.UserProfileResponse)
+	var filterTenantID string
+
+	if profile != nil {
+		if profile.Role == domain.RoleSuperAdmin {
+			// Super Admin can see everything or filter by a specific tenant if requested
+			filterTenantID = requestedTenantID
+		} else if profile.Role == domain.RoleTenantAdmin {
+			// Tenant Admin can only see their own tenant logs (or manageable ones)
+			// For now, lock to their primary tenant or requested one IF it's in their manageable list
+			if profile.TenantID != nil {
+				filterTenantID = *profile.TenantID
+			}
+			
+			// If they requested a specific tenant, verify they can manage it
+			if requestedTenantID != "" && requestedTenantID != filterTenantID {
+				canManage := false
+				for _, t := range profile.ManageableTenants {
+					if t.ID == requestedTenantID {
+						canManage = true
+						break
+					}
+				}
+				if !canManage {
+					return errorJSON(c, fiber.StatusForbidden, "forbidden: cannot view logs for this tenant")
+				}
+				filterTenantID = requestedTenantID
+			}
+		} else {
+			return errorJSON(c, fiber.StatusForbidden, "forbidden")
+		}
+	}
+
+	logs, err := h.repo.FindPage(c.Context(), limit+1, cursor, filterTenantID)
 	if err != nil {
 		return errorJSON(c, fiber.StatusInternalServerError, "Failed to retrieve audit logs")
 	}