fix: invalid schema type for LogicalVectorSearchLookupJoin

[silver-ymz]

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What's changed and what's your intention?

close #23891

CorrelatedTopNToVectorSearchRule only specifies following logical plan pattern.

LogicalApply { type: LeftOuter, on: true, correlated_id, max_one_row: true }
 └─ LogicalProject { exprs: [[Coalesce(array_agg($expr1 order_by($expr2 ASC)), ARRAY[]) as $expr3] }
    └─ LogicalAgg { aggs: [array_agg($expr1 order_by($expr2 ASC))] }
       └─ LogicalTopN { order: [$expr2 ASC] }
          └─ LogicalProject { exprs: [Row(...) as $expr1, L2Distance(CorrelatedInputRef { index: 0, correlated_id: 1 }, items.embedding) as $expr2] }

This logical plan should have schema same as array(row(...)), so the inner struct type should be an unnamed struct.

Checklist

• I have written necessary rustdoc comments.
• I have added necessary unit tests and integration tests.
• I have added test labels as necessary.
• I have added fuzzing tests or opened an issue to track them.
• My PR contains breaking changes.
• My PR changes performance-critical code, so I will run (micro) benchmarks and present the results.
• I have checked the Release Timeline and Currently Supported Versions to determine which release branches I need to cherry-pick this PR into.

Documentation

• My PR needs documentation updates.

Release note

[Copilot]

Pull request overview

This PR fixes an issue where LogicalVectorSearchLookupJoin was creating a struct type with named fields when it should use unnamed fields. The fix involves changing StructType::unnamed() to accept an iterator directly, eliminating unnecessary allocations and improving code ergonomics.

• Refactored StructType::unnamed() to accept impl IntoIterator<Item = DataType> instead of Vec<DataType>
• Fixed VectorSearchLookupJoinCore::struct_type() to use unnamed struct fields
• Removed unnecessary .collect() calls and unused imports across the codebase

Reviewed changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
src/common/src/types/struct_type.rs	Modified unnamed() method signature to accept any iterator of DataType
src/frontend/src/optimizer/plan_node/logical_vector_search_lookup_join.rs	Fixed to use StructType::unnamed() instead of StructType::new(), ensuring correct unnamed struct schema
src/frontend/src/optimizer/rule/unify_first_last_value_rule.rs	Removed unnecessary .collect() call when building field types
src/frontend/src/binder/expr/value.rs	Removed unused itertools::Itertools import and .collect_vec() call
src/common/src/array/struct_array.rs	Removed .collect() calls in from_protobuf() and From<DataChunk> implementation
src/common/src/array/data_chunk.rs	Simplified struct type creation by removing intermediate .collect()

[wenym1]

Rest LGTM. Thanks for the quick fix!

[wenym1]

Shall we have a unified method in StructType like fn row_expr_type(types: impl Iterator<Item = DataType>) and call in both here and in bind_row so that we can explicitly declare that here we construct the struct type in the same way as row?

[silver-ymz]

updated in new commit