Support struct type in Scribe

[xd1313113]

Issue #, if available:
None
Description of changes:
Adds support for transpiling PartiQL struct types into multiple SQL dialects, including struct field navigation and struct construction, and expands golden test coverage for these cases.

Changes:

Add new struct.sql input fixture plus expected outputs for PartiQL, Trino, Spark, and Redshift.
Update Spark struct construction to use NAMED_STRUCT, and adjust Spark EXCLUDE golden outputs accordingly.
Extend Trino/Redshift rewrites to handle constructed structs (and, for Redshift, to hard-fail unsupported constructed-struct field access).

Each Tests are manually tested on each sql engine.

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[Copilot]

Pull request overview

Adds support for transpiling PartiQL struct types into multiple SQL dialects, including struct field navigation and struct construction, and expands golden test coverage for these cases.

Changes:

• Add new struct.sql input fixture plus expected outputs for PartiQL, Trino, Spark, and Redshift.
• Update Spark struct construction to use NAMED_STRUCT, and adjust Spark EXCLUDE golden outputs accordingly.
• Extend Trino/Redshift rewrites to handle constructed structs (and, for Redshift, to hard-fail unsupported constructed-struct field access).

Reviewed changes

Copilot reviewed 13 out of 13 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
src/test/resources/outputs/trino/basics/struct.sql	New Trino golden outputs covering struct selection, navigation, wildcard expansion, and construction.
src/test/resources/outputs/spark/basics/struct.sql	New Spark golden outputs using NAMED_STRUCT for struct construction and field access.
src/test/resources/outputs/spark/basics/exclude.sql	Updates Spark EXCLUDE golden outputs to use NAMED_STRUCT instead of STRUCT(... AS ...).
src/test/resources/outputs/redshift/basics/struct.sql	New Redshift golden outputs using OBJECT(...) and documenting unsupported constructed-struct field access.
src/test/resources/outputs/partiql/basics/struct.sql	New PartiQL golden outputs for struct behaviors (baseline dialect).
src/test/resources/inputs/basics/struct.sql	New input fixture covering struct cases (navigation, dot-star, construction, filtering, join, subquery).
src/test/resources/catalogs/default/T_ALL_TYPES.ion	Updates catalog schema to include col_struct_simple and col_struct_nested with nested struct fields.
src/main/kotlin/org/partiql/scribe/targets/trino/utils/TrinoExcludeUtils.kt	Extends Trino ROW reconstruction to also handle RexStruct operands; adjusts UNKNOWN type handling.
src/main/kotlin/org/partiql/scribe/targets/trino/TrinoRewriter.kt	Wraps constructed structs in CAST-to-ROW when used in path navigation; rewrites nested RexStruct fields.
src/main/kotlin/org/partiql/scribe/targets/trino/TrinoAstToSql.kt	Adds a defensive error path for ExprStruct reaching AST-to-SQL conversion.
src/main/kotlin/org/partiql/scribe/targets/spark/SparkAstToSql.kt	Switches struct construction emission to NAMED_STRUCT and adds struct-field emission visitor.
src/main/kotlin/org/partiql/scribe/targets/redshift/RedshiftRewriter.kt	Throws a targeted error when accessing fields on constructed structs (unsupported in Redshift).
api/Scribe.api	Captures new public API surface from added visitor overrides.

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[johnedquinn]

Overall looks good. Minor comments.

[XuechunHHH]

LGTM! 🚀