Fix TestInsert for Kotlin and Java

[oyvindberg]

Summary

TestInsert now works properly for all three JVM languages:

• Kotlin: Fixed by adding default parameter values for Defaulted fields
• Java: Implemented fluent Inserter<U,R> pattern since Java lacks default parameters

Java Usage

// Simple insert
var row = testInsert.personBusinessentity().insert(c);

// With required parameters
var person = testInsert.personPerson(entityId, "EM", firstName).insert(c);

// Customize with .with() before inserting
var product = testInsert.productionProduct(...)
    .with(row -> row.withName(new Name("Custom")))
    .insert(c);

Changes

• Add Inserter<U,R> interface in foundations-jdbc with of(), with(), insert()
• Generate Inserter-based methods for Java, default parameters for Kotlin/Scala
• Fix Java code generation in ComputedTestInserts:
  • Use jvm.New() for proper constructor calls
  • Fully qualify Defaulted.UseDefault
  • Use string constructors for Int2Vector/Vector
  • Language-native list access for enum selection
• Update Java tests to use new API
• Update documentation with Java examples

Test plan

• All Java tests pass
• All Scala tests pass
• All Kotlin tests pass
• Regenerated code for all databases (PostgreSQL, MariaDB, DuckDB, Oracle, SQL Server)

🤖 Generated with Claude Code