FOCUS 1.4 phase 4: add FOCUS 1.4-preview ingestion

[flanakin]

Parent: #2120
Depends on: #2129 (phase 3)

Goal

Add FOCUS 1.4 ingestion support as a preview schema. FOCUS 1.4 is still in working_draft (last commit 2026-01-09) and may churn before ratification. Hub schema version: `v1_4`.

Scope

`IngestionSetup_v1_4.kql` (new)

• Copy `IngestionSetup_v1_3.kql` as the starting point.
• Rename `_v1_3` -> `_v1_4`, `FOCUS 1.3` -> `FOCUS 1.4-preview`.
• Remove `ProviderName` and `PublisherName` columns from `Costs_final_v1_4` (removed in 1.4 per spec).
• Update `Costs_transform_v1_4` projection to drop those columns.
• Expand `ContractCommitment_final_v1_4` with FOCUS 1.4 column additions:
  • `BenefitCategory` (string)
  • `ContractCommitmentApplicability` (dynamic / JSON)
  • `Created` (datetime)
  • `DiscountPercentage` (real)
  • `DurationType` (string)
  • `FulfillmentInterval` (string)
  • `LastUpdated` (datetime)
  • `LifecycleStatus` (string)
  • `Model` (string)
  • `OfferCategory` (string)
  • `PaymentInterval` (string)
  • `PaymentModel` (string)
  • `PaymentUpfrontPercentage` (real)
  • `PricingCurrencyContractCommitmentCost` (real)
• Add corresponding raw columns to `ContractCommitment_raw` in `IngestionSetup_RawTables.kql`.
• Wire `v1_4` into `app.bicep` and `.build.config`.

Out of scope

• `HubSetup_v1_4.kql` -> phase 5
• New Invoice dataset (mentioned in 1.4 working_draft) -> deferred until spec stabilizes

Branch

`flanakin/focus14-phase4-ingestion-1.4` off `flanakin/focus14-phase3-contractcommitment`. PR target: phase 3 branch.

Done when

• New file deploys cleanly.
• Pester tests pass.
• Bicep compiles.