Ask your builder for their definitions.

You should be able to follow their guidelines at their supplier and hit the budget if its legitimate.

My lighting budget is defined at "light fixtures, FOB jobsite" which includes the fixture, sales tax, light bulbs, delivery and/or shipping. It also includes the cost of having your fixture provided with proper length cabling and chain for taller ceilings.

I often give my clients a line by line fixture worksheet to help them make selections on budget (numbers based on a previous project), but usually they don't care until after they blow a budget.

Some builders include "recessed lighting" in their fixture allowance. That should be stated either way as it can be a significant item. I now include under cabinet lighting fixtures as they vary significantly.

I've seen million dollar homes with $6-8K worth of fixtures that were reasonable, and seen single dining room fixtures from $10-25k in the same price range of homes. Just finished one with real crystal in the master closet.

Its best to select early, prior to the end of framing cycle, if not before groundbreaking or contract signing.

What does your construction contract say?

It says “interior fireplace budget $7000” and “lighting budget $7000”-basically to that effect

The description above is typical, and usually works until a client doesn't understand it the way the builder intended. "I selected my granite in China and I'm under budget at 20% of local costs. Can you handle it from here?"

Those items can be figured differently. While fixtures are often figured FOB jobsite, fireplaces are figured "installed" in my budgets (firebox, all the flues & pieces, installation labor=allowance).

In a previous post, you indicated a 36-48" Ortal. Your allowance should be enough but why not just go select and end the mystery (eliminate it as an allowance). Depending on cost of labor in your market area, you should have enough allowance for a really nice traditional fireplace or this size of Ortal linear.