The discriminator typed-bind render-tier code-string pins duplicate what the SQL baselines already pin

The enum-discriminator fix landed the same fact at two tiers, and the cheaper one is the authoritative tier. Four assertions now read the emitted method body as a string to check that a @discriminator(value:) operand is DSL.val(..., <COL>.getDataType()): RootLauncherRendererTest.discriminatedSource_appliesDiscriminatorFilter, discriminatedSource_joinedDetailOnClause_comparesAgainstAColumnTypedBind, discriminatedSource_crossTableGate_comparesAgainstAColumnTypedBind, and TypeFetcherGeneratorTest.queryTableInterfaceField_discriminatorSubselectGate_qualifiesOffTableInstance. The same four emission sites are pinned as rendered SQL by the enum-discriminated fixture families: RootLauncherSqlBaselineTest carries the IN filter, the joined-detail ON clause and the cross-table gate as cast(? as "public"."content_kind") / "subject_kind", DmlSqlBaselineTest carries the values(...) write, and BatchedChildSqlBaselineTest carries the batched arms. The SQL baselines are what development-principles.adoc names as the code-string ban’s replacement ("the compile and execution tiers replace them"), so the render-tier strings are the redundant copy, and the one that breaks on any javapoet or fragment refactor that leaves behaviour intact.

Two smaller things travel with it. TypeFetcherGeneratorTest’s carve-out is documented as being about qualification ("the discriminator column must qualify to the table jOOQ renders in the FROM clause"), and its two siblings truncate their pinned string at `.as("__discriminator__") and .in( respectively for exactly that reason; the subselect-gate one now pins the operand as well, which is scope its stated rationale does not cover. And RootLauncherRendererTest’s class javadoc still says "Structural properties only", explaining at length why body strings are avoided for the connection arm, while the class holds 35 `contains( assertions.

The work is to decide which render-tier pins earn their place, delete the rest, and make the surviving carve-out’s rationale explicit in the class javadoc so the next reader knows why these are the exception. Filed at the enum-discriminator item’s Done gate, where the additions were contract-conformant (its spec asked for them) but the redundancy was not weighed.