Costs() column reference has drifted from the deployed schema since hubs v12

🐛 Problem

The Costs() table in src/queries/finops-hub-database-guide.md has drifted from the deployed schema. The guide is read by the GenAI plugins and agents that build queries against a hub, so a column that is absent from the table is effectively a column the agent will not use, and a name the table still lists is one the agent will write into a query that then fails.

Checked against two unrelated hubs, which both return 155 columns from Costs():

• 27 columns the table does not list at all — including the FOCUS 1.2 additions ServiceSubcategory, SkuMeter, SkuPriceDetails, CapacityReservationId, CapacityReservationStatus, CommitmentDiscountQuantity, CommitmentDiscountUnit, PricingCurrency and InvoiceId.
• 3 columns listed under names that hubs v12 renamed away from — x_InvoiceId, x_PricingCurrency, x_SkuMeterName. Neither hub has them; both have the new names.
• 1 type mismatch — x_SkuLicenseQuantity is documented as long; the deployed schema has int. (docs-mslearn/toolkit/hubs/data-model.md says String for the same column, so that file needs a look too.)

The renames are the ones announced in announce/2025/2025-08_non-breaking-changes-in-hubs-12.md:

Renamed x_InvoiceId       -> InvoiceId
Renamed x_PricingCurrency -> PricingCurrency
Renamed x_SkuMeterName    -> SkuMeter
Added   ServiceSubcategory
Added   SkuPriceDetails

So this is v12 drift rather than a disagreement about what the schema should be.

👣 Repro steps

Costs() | getschema | project ColumnName, ColumnType | order by ColumnName asc

Compare the result with the Costs() table in the guide.

🤔 Expected

The table reference matches what Costs() returns. Its own introduction says it "lists the columns produced in the All available columns query", and that query is Costs() plus a set of extend steps, so every Costs() column belongs in it.

🔧 Environment

• Affected file: src/queries/finops-hub-database-guide.md on dev
• FinOps hub version: v12 and later

ℹ️ Additional context

Descriptions for the missing columns already exist elsewhere in this repo — docs-mslearn/toolkit/help/data-dictionary.md for the FOCUS columns, and the Copilot Studio template's schema reference for the x_ ones — so filling the gaps needs no new definitions.

Two of them intersect existing issues and are worth a closer look during review: x_CommitmentDiscountSpendEligibility and x_CommitmentDiscountUsageEligibility, see #2279 and #2287.

Start with src/queries/finops-hub-database-guide.md and compare its Costs() table with the provided Costs() | getschema query. Check announce/2025/2025-08_non-breaking-changes-in-hubs-12.md, docs-mslearn/toolkit/help/data-dictionary.md, and docs-mslearn/toolkit/hubs/data-model.md for the renamed, missing, and mismatched entries. Done means the guide matches the deployed v12 schema and any related type discrepancy is reviewed.