[TS PBT] Focus original property search using observed entry relations

[CaelmBleidd]

PBT numeric relations currently have no consumer in original-property symbolic search. Add adapter-owned ENTRY_ARGUMENT observations, captured from the ordered original inputs before the callback runs, and bind their numeric values through the existing EtsIR input slots.

searchFocusedOnEntryRelation explicitly adds the negation of a sampled equality/order relation to the same declared support, original precondition and original property-failure query. The existing unfocused API remains available. The result retains the applied binding and complete inference provenance, so a focused no-finding result cannot be presented as exhaustion of the original domain. Incompatible property/support/source identities, unsupported points, changed snapshots and ambiguous bindings cannot activate the focus.

This first slice of #398 is restricted to root numeric entry arguments. It does not infer exact bindings for arbitrary user hooks, return/intermediate values, aliases or nested invocations. Executable-body build status remains UNVERIFIED; exactness concerns the adapter-owned argument transport only. Each call still creates a search: shared sessions, scheduling the unfocused share and repeated feedback rounds remain with #481/#399/#355. #398 remains open.

Stacked on #539 (caelmbleidd/pbt-scalar-relations) at 983f99f5c69f5197fa3c5a30af41d575c75596f9.

Validation: 220 PBT Kotlin tests, 100 FastCheck Kotlin tests and 199 native adapter tests passed, along with strict Detekt on every changed Kotlin file and git diff --check. With the same independent original predicate left !== 1, two real native observation sets guide USVM to [1, 0] and [1, 2]; both violations are checked in native execution. Tests also cover NaN, original admission, an always-true original oracle, infeasible focused support and rejected bindings. No benchmark campaign was run.