Add features bundle resource

[Daniel114510]

Changes

Adds features as a bundle resource type, so a Feature Engineering feature can be declared in databricks.yml and deployed, updated and destroyed like any other resource.

UpdateFeature accepts description and nothing else, so the adapter sends a static update_mask=description; every other field is excluded at plan level, with full_name, source and function marked recreate_on_changes from the spec's IMMUTABLE annotations. Literal catalog and schema names in full_name are rewritten into ${resources.…} references so a feature deploys after the catalog and schema it lives in.

Why

Features are currently created through the Python client or the API. Onboarding Features to direct engine is part of the proper DAB support effort for the Feature Engineering API.

Tests

• go test ./bundle/... ./libs/... ./internal/... ./cmd/... ./experimental/ssh/... . — passed
• go test ./acceptance — passed
• task generate-check — no drift
• task checks, task fmt — passed

Acceptance tests added:

• bundle/resources/features/basic — full lifecycle, request trace
• bundle/resources/features/lifecycle — cloud-capable, provisions its own table
• bundle/resources/features/remote-delete — out-of-band delete drift
• bundle/deployment/bind/feature — bind and unbind
• bundle/invariant/configs/feature.yml.tmpl — invariant coverage
• libs/testserver/feature.go — fake create/get/update/delete
• cmd/experimental/workspace_open_test.go — features URL and resource-type lists

Live-tested against a workspace with lite-swapped Feature Store. Tested for Delta-sourced batch feature, a Kafka-stream-sourced feature, and a sawtooth-window feature. For each feature: CRUD, bind and unbind, a second bundle plan reported no changes after create and update, changing an immutable field planned a recreate every time.

[eng-dev-ecosystem-bot]

Integration test report

Commit: 17080fa

Run: 37995942239

	Env	❌​FAIL	✅​pass	🙈​skip	Time
❌​	aws linux-2core-8gb	3	276	22	5:14
❌​	aws-windows-latest-4core-16gb	3	278	20	5:25
❌​	azure linux-2core-8gb	3	275	22	5:08
❌​	azure-windows-latest-4core-16gb	3	277	20	6:05
❌​	gcp linux-2core-8gb	3	276	22	5:14
❌​	gcp-windows-latest-4core-16gb	3	278	20	6:09

	Test Name	aws linux-2core-8gb	aws-windows-latest-4core-16gb	azure linux-2core-8gb	azure-windows-latest-4core-16gb	gcp linux-2core-8gb	gcp-windows-latest-4core-16gb
❌​	TestAccept	❌​F	❌​F	❌​F	❌​F	❌​F	❌​F
❌​	TestAccept/bundle/resources/features/lifecycle	❌​F	❌​F	❌​F	❌​F	❌​F	❌​F
❌​	TestAccept/bundle/resources/features/lifecycle/DMS=true	❌​F	❌​F	❌​F	❌​F	❌​F	❌​F