PB-078: Preview tags match the docs

State: Proposed. Not approved for implementation. Priority: P1 (mandatory: required). Owner when approved: Master product (unassigned).

1. PR title and ID#

Tag every docs-Preview feature in the app, or correct the docs (PB-078)

2. Business problem#

Organizations hide Preview features by policy (show_preview). Features the docs call Preview but the app doesn't tag can't be hidden, so a locked-down organization still exposes them. AGENTS.md requires untested Fabric integrations to keep Preview labeling.

3. Current verified behavior#

app/ui/features.js PREVIEW_FEATURES has 19 ids (fabricRun through workloads); previewTag() hides tagged nodes when show_preview is false. app/tests/ui.test.cjs checks Workloads is Preview.
docs/metadata-guide.md labels as Preview: batches (batch_by, line 142), reliability objectives (line 243), release records (line 293), who can promote (line 319), column lineage (line 511). None has a Preview id. Batches, objectives and release records are engine behaviors with little or no UI; column lineage has no UI (FEAT-META-17).

4. Desired behavior#

For each docs-Preview capability: if it has a UI surface, that surface carries a Preview id and is hidden with Preview off; if it has none, the engine respects show_preview (for example the promote card's release-record note) or the docs say "engine behavior, not hideable" and why.

5. In scope and out of scope#

In scope: ids for surfaces that exist (promote card release note and role check, batch settings in the entity editor if present); docs wording; a UI test that keeps the two lists aligned. Out of scope: new screens for lineage or objectives (PB-081, PB-047).

6. Architecture and files#

app/ui/features.js, app/ui/meta.js (promote card), docs/metadata-guide.md, app/tests/ui.test.cjs, docs/README.md features table if it lists Preview.

7. Functional requirements#

New ids follow the existing naming (camelCase keys, plain names).
With show_preview false the tagged surfaces disappear, and promote still works without them.
The test parses docs/*.md for "(Preview)" headings and fails when a heading has no id and no documented exception.

8. Nonfunctional requirements#

No new rail items (the rail is full at 8).

9. Dependencies#

None.

10. Security and compatibility#

Hiding a check from the UI must not skip the check itself: who-can-promote stays enforced when its note is hidden.

11. Acceptance criteria#

Every docs-Preview feature has an id or a documented exception.
With Preview off, none of the tagged surfaces shows; promote still runs its gates (test).
UI tests pass.

12. Unit and integration tests#

Extend app/tests/ui.test.cjs: docs-vs-ids alignment, hidden-when-off for each new id.

13. Manual verification#

Settings > Preview features off, open an entity and the promote card, confirm tagged parts are gone.

14. Documentation#

docs/metadata-guide.md Preview wording; docs/README.md if it lists Preview features.

15. Rollback#

Revert; ids are additive.

16. Definition of Done#

Merged, UI tests green, FEAT-SHL-05 limitation removed in the inventory after review.