lgj-abi: bind the real OGAR ClassView provider behind a feature

[AdaWorldAPI]

What

edge_participation answered FieldMask::FULL for every classid — the fixture's constant. This binds ogar_class_view::OgarClassView (the ontology-backed provider over ogar_vocab) behind a new ogar-classview feature, so participation derives from each class's real field basis instead.

Closes the §4-NG3 named seam ("a real ontology/cache provider is a NAMED SEAM") on the provider half.

Measured

examples/classview_census.rs (new):

	distinct participation masks over 98 registered classes
fixture	1 (0xFFFFFFFF for all 98)
real provider	12 (field counts 0–13)

An unregistered classid participates in nothing rather than everything — an unknown class is not a licence to traverse every facet.

The [patch] is load-bearing, not cosmetic

ogar-class-view pulls lance-graph-contract by git branch; this crate pulls it by path. Cargo does not unify a git SourceId with a path SourceId, so without the patch the build carries two lance-graph-contract crates and therefore two incompatible ClassView traits — the same trap recorded in tesseract-rs for ogar-doc-ir. Verified: cargo tree shows one, both resolving to the local path.

What binding it EXPOSED — the finding

The generated row store draws classids from 0..16 (ROWSTORE_CLASS_CARDINALITY); every vocabulary classid is >= 0x0100. The two domains are disjoint, so a generated store under the real provider hops nothing.

That is not a defect in the provider — it is the measurement of how far the fixture reached. FieldMask::FULL is the answer that never disagrees, which is exactly why it could not be falsified in place; the seam read as closed-enough for two waves because nothing in the suite could tell the two providers apart. The remaining fixture is the row content, not the layout or the kernels; Lance-loaded SoA rows are what make the bound provider observable end-to-end. Pinned by hop_under_the_real_provider_narrows_by_class, not left in prose.

Two gated tests, each with a contrasting twin

Neither is deleted or suppressed. Each asserts the opposite fact on the same inputs:

gated OFF under the feature	paired ON twin
edge_participation_covers_exactly_the_low_32_bits (all 32)	the_real_provider_narrows_rather_than_widens (unregistered → 0; richest registered class → exactly its low-13 prefix)
hop_matches_the_pinned_rowstore_regression_10_19_29 (19/29)	hop_under_the_real_provider_narrows_by_class (empty — and two-sided: the provider still answers 13 for 0x0103, so emptiness is the store's domain, not a dead provider)

Gates

• Default (feature OFF): 134/134 rust, 447/447 Java (304 core + 143 consumer) — unchanged.
• Feature ON: 136/136.
• Disable-run (edge_participation's ogar arm returns FULL): 5 tests red, green on restore.
• clippy --all-targets -- -D warnings and fmt --check clean in both configurations.
• G11 contract-import fence green: class_view, canonical_node, ontology, facet only.

Board artifacts land in this commit: LATEST_STATE.md entry and EPIPHANIES.md E-BINDING-A-REAL-PROVIDER-MEASURES-THE-FIXTURE-1.

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