feat(python): accept expressions in update filters (#3876)

## Summary
- allow Python sync, async, and remote table updates to accept type-safe
`Expr` filters
- serialize expression filters before invoking the existing update
implementation
- cover numeric-looking text and apostrophe-containing text in sync and
async regression tests

## Root cause
`Table.update` was the remaining Python write path that required callers
to construct a raw SQL predicate. Dynamic text interpolated without SQL
literal encoding could therefore be parsed as an integer, float, or
unterminated string instead of Utf8. The expression API already encodes
literals safely for query and delete filters.

## Validation
- `cd python && .venv/bin/pytest
python/tests/test_table.py::test_update_async
python/tests/test_table.py::test_update_expr_filter_literals_async
python/tests/test_table.py::test_update
python/tests/test_table.py::test_update_expr_filter_literals -q`
- `cd python && .venv/bin/pytest python/tests/test_expr.py -q`
- `cd python && .venv/bin/ruff format --check .`
- `cd python && .venv/bin/ruff check .`

Fixes #1869

<!-- lance-gatekeeper-fix:v1 agent=01f1e7b69c65e8b6d3b3c1e1a7918179
generation=1 -->

---------

Co-authored-by: Gatefixer <313497061+lancedb-gatefixer[bot]@users.noreply.github.com>
Co-authored-by: Xuanwo <github@xuanwo.io>

python/src/query.rs

@@ -1,6 +1,7 @@
 // SPDX-License-Identifier: Apache-2.0
 // SPDX-FileCopyrightText: Copyright The LanceDB Authors
 
+use std::collections::HashMap;
 use std::sync::Arc;
 use std::time::Duration;
 
@@ -325,6 +326,7 @@ pub struct PyQueryRequest {
     pub filter: Option<PyQueryFilter>,
     pub full_text_search: Option<PyLanceDB<FtsQuery>>,
     pub select: PySelect,
+    pub select_source_columns: Option<HashMap<String, String>>,
     pub fast_search: Option<bool>,
     pub with_row_id: Option<bool>,
     pub use_lsm: Option<bool>,
@@ -355,6 +357,7 @@ impl From<AnyQuery> for PyQueryRequest {
                 full_text_search: query_request
                     .full_text_search
                     .map(|fts| PyLanceDB(fts.query)),
+                select_source_columns: PySelect::source_columns(&query_request.select),
                 select: PySelect(query_request.select),
                 fast_search: Some(query_request.fast_search),
                 with_row_id: Some(query_request.with_row_id),
@@ -380,6 +383,7 @@ impl From<AnyQuery> for PyQueryRequest {
                 offset: vector_query.base.offset,
                 filter: vector_query.base.filter.map(PyQueryFilter),
                 full_text_search: None,
+                select_source_columns: PySelect::source_columns(&vector_query.base.select),
                 select: PySelect(vector_query.base.select),
                 fast_search: Some(vector_query.base.fast_search),
                 with_row_id: Some(vector_query.base.with_row_id),
@@ -412,6 +416,25 @@ impl From<AnyQuery> for PyQueryRequest {
 #[derive(Clone)]
 pub struct PySelect(Select);
 
+impl PySelect {
+    fn source_columns(select: &Select) -> Option<HashMap<String, String>> {
+        match select {
+            Select::Expr(pairs) => Some(
+                pairs
+                    .iter()
+                    .filter_map(|(output, expr)| match expr {
+                        lancedb::expr::DfExpr::Column(column) if column.relation.is_none() => {
+                            Some((output.clone(), column.name.clone()))
+                        }
+                        _ => None,
+                    })
+                    .collect(),
+            ),
+            _ => None,
+        }
+    }
+}
+
 impl<'py> IntoPyObject<'py> for PySelect {
     type Target = PyAny;
     type Output = Bound<'py, Self::Target>;