Add "Create on Order" settings for Service type products

Summary

When creating a product and selecting the type "Service", the system currently only hides the stock/inventory related options. It does not offer any of the extra settings that are normally expected for a service, such as automatically creating work (a task or project) when the service is sold, or choosing how the service's progress should be tracked. This request asks for these missing settings to be added.

Current Behaviour

Right now, selecting "Service" as the product type only removes options like weight, tracking by lot/serial number, and other stock-related settings. Nothing new is added in their place. A Service product behaves almost exactly like a regular product, except it skips inventory management.

Problem

Businesses that sell services (consulting, installation, maintenance, support hours, etc.) usually need more than just an invoice. They need a way to:

• Know that selling a service should trigger some actual work to be done
• Assign that work to a team or person
• Track how much of the service has been completed before billing the customer

None of this is currently possible. A service is sold like a simple item, with no connection to any follow-up work.

Requested Feature

1. "Create on Order" option

When setting up a Service product, add a setting that lets the user choose what should happen automatically once the service is sold (i.e., once the order is confirmed):

• Nothing – no follow-up action is created (this should be the default, to match current behaviour)
• Create a Task – a task is automatically created so the work can be assigned and tracked
• Create a Project and a Task – a full project along with a task is created, useful for larger services that involve multiple steps

This would connect the Sales area with the Project/Task area, which today are completely disconnected.

2. "Service Tracking" / delivery method option

Add a setting to define how the "amount delivered" of a service should be measured, especially when the Invoicing Policy is set to "Delivered Quantities". Suggested options:

• Manually entered – someone manually updates how much of the service has been completed
• Based on logged work hours (timesheet) – if hours are logged against the related task, that amount automatically counts as the delivered quantity

This links naturally with the Invoicing Policy feature that already exists in the system, making "Delivered Quantities" invoicing actually usable for services (currently there is no reliable way to know how much of a service has been "delivered", since only manual and stock-based methods exist).

3. Show these settings only for Service products

These new settings should only appear when the product type is set to "Service", so that regular goods are not affected and the product creation screen stays clean and relevant.

Why This Matters

• Many service-based businesses (agencies, consultants, maintenance providers) cannot properly use the system today because selling a service does nothing beyond creating an invoice line.
• It closes the gap between the Sales module and the Project/Timesheet module, which currently have no connection at all.
• It makes the existing "Delivered Quantities" invoicing option actually meaningful for services, instead of only working reliably for physical goods.
• This brings the product experience closer to what most competing systems offer, which is a common expectation for anyone evaluating this system for a service-based business.

Suggested Priority

Medium-High — this is a commonly expected feature for any business that primarily sells services rather than physical goods, and its absence limits adoption for that entire segment of users.