fix!: replace ProofExpr::get_column_references with ProofExpr::get_column_fields

[iajoiner]

Rationale for this change

We have a hidden bug, namely ProofExpr::get_column_references only makes sense if they are on a source table since in query_proof.rs that's how they are eventually used. Hence nothing other than TableExec, LegacyFilterExec and GroupByExec should actually be sources of these column references. In order to achieve that the first step is that we only allow deprecated proof plans, LegacyFilterExec and GroupByExec, to use ColumnFields of ProofExprs they use since these are actually reliably on source tables. Eventually get_column_references is scheduled to be removed everywhere since what datafusion and the planner consider to be in TableExecs are precisely the columns of source tables we need.

[codecov]

Codecov Report

❌ Patch coverage is 81.66667% with 11 lines in your changes missing coverage. Please review.
✅ Project coverage is 96.69%. Comparing base (4cba4b0) to head (3c9d4e1).
⚠️ Report is 36 commits behind head on main.

Files with missing lines	Patch %	Lines
...roof-of-sql/src/sql/proof_exprs/inequality_expr.rs	0.00%	3 Missing ⚠️
.../proof-of-sql/src/sql/proof_exprs/subtract_expr.rs	0.00%	3 Missing ⚠️
...ates/proof-of-sql/src/sql/proof_exprs/cast_expr.rs	0.00%	2 Missing ⚠️
...of-of-sql/src/sql/proof_exprs/scaling_cast_expr.rs	0.00%	2 Missing ⚠️
...oof-of-sql/src/sql/proof_exprs/placeholder_expr.rs	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1087      +/-   ##
==========================================
- Coverage   96.72%   96.69%   -0.04%     
==========================================
  Files         302      302              
  Lines       58840    58909      +69     
==========================================
+ Hits        56915    56961      +46     
- Misses       1925     1948      +23     

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[Copilot]

Pull request overview

This PR refactors the ProofExpr trait to replace the get_column_references method with get_column_fields, addressing a hidden bug where column references only make sense when they're on source tables. The change separates the collection of column metadata (ColumnField) from the association with specific table references (ColumnRef).

Key changes:

• Renamed ProofExpr::get_column_references to ProofExpr::get_column_fields with updated signature
• Updated all expression implementations to collect ColumnField instead of ColumnRef
• Modified LegacyFilterExec and GroupByExec to convert ColumnField to ColumnRef using table context

Reviewed changes

Copilot reviewed 17 out of 17 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
proof_expr.rs	Updated trait method from get_column_references to get_column_fields, changing return type from ColumnRef to ColumnField with updated documentation
column_expr.rs	Updated to use get_column_fields and insert ColumnField objects via get_column_field() helper
add_expr.rs, subtract_expr.rs, multiply_expr.rs	Updated binary arithmetic expressions to use get_column_fields
and_expr.rs, or_expr.rs, not_expr.rs	Updated logical expressions to use get_column_fields
equals_expr.rs, inequality_expr.rs	Updated comparison expressions to use get_column_fields
cast_expr.rs, scaling_cast_expr.rs	Updated cast expressions to use get_column_fields
literal_expr.rs, placeholder_expr.rs	Updated leaf expressions with empty get_column_fields implementations
dyn_proof_expr.rs	Added ColumnField to imports
legacy_filter_exec.rs	Updated to collect ColumnFields and convert to ColumnRefs using table reference
group_by_exec.rs	Updated to collect ColumnFields and convert to ColumnRefs using table reference

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[github-actions]

This PR has been marked as stale due to 30 days of inactivity. It will be closed in 7 days if no further activity occurs.