feat(nodejs): add col() expression builder for camelCase column names

## Summary

Fixes #3211 by exposing the shared Rust/DataFusion expression builder through Node bindings. Case-sensitive references such as `col("firstName")` can be composed and passed to `where()`, while SQL strings remain supported.

The expression-object representation follows [the design requested on #3290](https://github.com/lancedb/lancedb/pull/3290#discussion_r3632371998). That earlier PR remains open; no claim is made that the issue was unclaimed or that maintainers have selected this implementation.

## Review corrections

- Construct the named native struct correctly and parse casts through `arrow_schema::DataType`.
- Preserve numeric values: use Int64 only for JavaScript safe integers; retain Float64 otherwise. Explicit `litInt` rejects unsupported numbers with a documented `RangeError`.
- Correct test syntax/API calls and align SQL assertions with the shared dialect, including reserved and case-sensitive names.
- Use typed, isolated temporary test tables with cleanup, and cover an actual large-number filter threshold.
- Document the public methods and commit generated API documentation.

Synced with current main `0bceaaf3` through a normal merge. The diff is limited to seven Node source/test/config files and eleven generated documentation files; no Rust core change.

## Validation

[Linux validation run](https://github.com/Ganesh1729-ui/lancedb/actions/runs/38244794288) on Node 24 / Rust 1.97.0 with the repository's `ci` profile and `remote,lancedb/metrics-otel` features:

- Rebuilt native addon, TypeScript build, Biome, Rust formatting and native Clippy pass.
- Expression/query/Arrow/table suites: **1,129 passed**; expression suite repeated: **42 passed**.
- Using the original JavaScript numeric dispatch with the rebuilt addon: **8 regressions fail, 2 controls pass**.
- Strict TypeDoc generation passes. Final local typing/docs/lint checks pass; the PR source equals the validated source except for the separate validation workflow, which is excluded from this PR.

Full provider/model/S3, other feature combinations and OS/Node matrices were not run in this follow-up. Upstream checks and maintainer review remain separate.

## AI assistance

AI was used for implementation, review and testing. No prior human review is claimed.

docs/src/js/classes/AutoQuery.md

@@ -469,29 +469,34 @@ where(predicate): this
 
 A filter statement to be applied to this query.
 
-The filter should be supplied as an SQL query string.  For example:
+The filter may be an SQL query string or an expression built with `col`,
+which preserves case-sensitive column names. For example:
 
 #### Parameters
 
-* **predicate**: `string`
+* **predicate**: `string` \| [`Expr`](Expr.md)
 
 #### Returns
 
 `this`
 
-#### Example
+#### Examples
 
 ```ts
 x > 10
 y > 0 AND y < 100
 x > 5 OR y = 'test'
+```
+
+```ts
+table.query().where(col("firstName").eq("Alice"));
+```
 
 Filtering performance can often be improved by creating a scalar index
 on the filter column(s).
 
 Calling this multiple times combines the filters with a logical AND rather
 than replacing the previous filter.
-```
 
 #### Inherited from
 

docs/src/js/classes/Expr.md

@@ -0,0 +1,365 @@
+[**@lancedb/lancedb**](../README.md) • **Docs**
+
+***
+
+[@lancedb/lancedb](../globals.md) / Expr
+
+# Class: Expr
+
+A SQL expression backed by the shared LanceDB expression builder.
+
+## Example
+
+```ts
+table.query().where(col("firstName").eq("Alice")).toArray();
+```
+
+## Constructors
+
+### new Expr()
+
+```ts
+new Expr(inner): Expr
+```
+
+#### Parameters
+
+* **inner**: `Expr`
+
+#### Returns
+
+[`Expr`](Expr.md)
+
+## Properties
+
+### inner
+
+```ts
+inner: Expr;
+```
+
+## Methods
+
+### add()
+
+```ts
+add(other): Expr
+```
+
+Add a value.
+
+#### Parameters
+
+* **other**: [`ExprLike`](../type-aliases/ExprLike.md)
+
+#### Returns
+
+[`Expr`](Expr.md)
+
+***
+
+### and()
+
+```ts
+and(other): Expr
+```
+
+Combine two predicates with AND.
+
+#### Parameters
+
+* **other**: [`Expr`](Expr.md)
+
+#### Returns
+
+[`Expr`](Expr.md)
+
+***
+
+### cast()
+
+```ts
+cast(dataType): Expr
+```
+
+Cast to an Arrow data type, such as "Int64".
+
+#### Parameters
+
+* **dataType**: `string`
+
+#### Returns
+
+[`Expr`](Expr.md)
+
+***
+
+### contains()
+
+```ts
+contains(substr): Expr
+```
+
+Test whether a string contains a substring.
+
+#### Parameters
+
+* **substr**: [`ExprLike`](../type-aliases/ExprLike.md)
+
+#### Returns
+
+[`Expr`](Expr.md)
+
+***
+
+### div()
+
+```ts
+div(other): Expr
+```
+
+Divide by a value.
+
+#### Parameters
+
+* **other**: [`ExprLike`](../type-aliases/ExprLike.md)
+
+#### Returns
+
+[`Expr`](Expr.md)
+
+***
+
+### eq()
+
+```ts
+eq(other): Expr
+```
+
+Compare for equality.
+
+#### Parameters
+
+* **other**: [`ExprLike`](../type-aliases/ExprLike.md)
+
+#### Returns
+
+[`Expr`](Expr.md)
+
+***
+
+### gt()
+
+```ts
+gt(other): Expr
+```
+
+Compare for greater than.
+
+#### Parameters
+
+* **other**: [`ExprLike`](../type-aliases/ExprLike.md)
+
+#### Returns
+
+[`Expr`](Expr.md)
+
+***
+
+### gte()
+
+```ts
+gte(other): Expr
+```
+
+Compare for greater than or equal to.
+
+#### Parameters
+
+* **other**: [`ExprLike`](../type-aliases/ExprLike.md)
+
+#### Returns
+
+[`Expr`](Expr.md)
+
+***
+
+### isIn()
+
+```ts
+isIn(values): Expr
+```
+
+Test membership in a list of values.
+
+#### Parameters
+
+* **values**: [`ExprLike`](../type-aliases/ExprLike.md)[]
+
+#### Returns
+
+[`Expr`](Expr.md)
+
+***
+
+### lower()
+
+```ts
+lower(): Expr
+```
+
+Convert a string to lowercase.
+
+#### Returns
+
+[`Expr`](Expr.md)
+
+***
+
+### lt()
+
+```ts
+lt(other): Expr
+```
+
+Compare for less than.
+
+#### Parameters
+
+* **other**: [`ExprLike`](../type-aliases/ExprLike.md)
+
+#### Returns
+
+[`Expr`](Expr.md)
+
+***
+
+### lte()
+
+```ts
+lte(other): Expr
+```
+
+Compare for less than or equal to.
+
+#### Parameters
+
+* **other**: [`ExprLike`](../type-aliases/ExprLike.md)
+
+#### Returns
+
+[`Expr`](Expr.md)
+
+***
+
+### mul()
+
+```ts
+mul(other): Expr
+```
+
+Multiply by a value.
+
+#### Parameters
+
+* **other**: [`ExprLike`](../type-aliases/ExprLike.md)
+
+#### Returns
+
+[`Expr`](Expr.md)
+
+***
+
+### ne()
+
+```ts
+ne(other): Expr
+```
+
+Compare for inequality.
+
+#### Parameters
+
+* **other**: [`ExprLike`](../type-aliases/ExprLike.md)
+
+#### Returns
+
+[`Expr`](Expr.md)
+
+***
+
+### not()
+
+```ts
+not(): Expr
+```
+
+Negate this predicate.
+
+#### Returns
+
+[`Expr`](Expr.md)
+
+***
+
+### or()
+
+```ts
+or(other): Expr
+```
+
+Combine two predicates with OR.
+
+#### Parameters
+
+* **other**: [`Expr`](Expr.md)
+
+#### Returns
+
+[`Expr`](Expr.md)
+
+***
+
+### sub()
+
+```ts
+sub(other): Expr
+```
+
+Subtract a value.
+
+#### Parameters
+
+* **other**: [`ExprLike`](../type-aliases/ExprLike.md)
+
+#### Returns
+
+[`Expr`](Expr.md)
+
+***
+
+### toSql()
+
+```ts
+toSql(): string
+```
+
+Serialize with the LanceDB SQL dialect, preserving column case.
+
+#### Returns
+
+`string`
+
+***
+
+### upper()
+
+```ts
+upper(): Expr
+```
+
+Convert a string to uppercase.
+
+#### Returns
+
+[`Expr`](Expr.md)

docs/src/js/classes/Query.md

@@ -543,29 +543,34 @@ where(predicate): this
 
 A filter statement to be applied to this query.
 
-The filter should be supplied as an SQL query string.  For example:
+The filter may be an SQL query string or an expression built with `col`,
+which preserves case-sensitive column names. For example:
 
 #### Parameters
 
-* **predicate**: `string`
+* **predicate**: `string` \| [`Expr`](Expr.md)
 
 #### Returns
 
 `this`
 
-#### Example
+#### Examples
 
 ```ts
 x > 10
 y > 0 AND y < 100
 x > 5 OR y = 'test'
+```
+
+```ts
+table.query().where(col("firstName").eq("Alice"));
+```
 
 Filtering performance can often be improved by creating a scalar index
 on the filter column(s).
 
 Calling this multiple times combines the filters with a logical AND rather
 than replacing the previous filter.
-```
 
 #### Inherited from
 

docs/src/js/classes/VectorQuery.md

@@ -825,29 +825,34 @@ where(predicate): this
 
 A filter statement to be applied to this query.
 
-The filter should be supplied as an SQL query string.  For example:
+The filter may be an SQL query string or an expression built with `col`,
+which preserves case-sensitive column names. For example:
 
 #### Parameters
 
-* **predicate**: `string`
+* **predicate**: `string` \| [`Expr`](Expr.md)
 
 #### Returns
 
 `this`
 
-#### Example
+#### Examples
 
 ```ts
 x > 10
 y > 0 AND y < 100
 x > 5 OR y = 'test'
+```
+
+```ts
+table.query().where(col("firstName").eq("Alice"));
+```
 
 Filtering performance can often be improved by creating a scalar index
 on the filter column(s).
 
 Calling this multiple times combines the filters with a logical AND rather
 than replacing the previous filter.
-```
 
 #### Inherited from
 

docs/src/js/functions/col.md

@@ -0,0 +1,21 @@
+[**@lancedb/lancedb**](../README.md) • **Docs**
+
+***
+
+[@lancedb/lancedb](../globals.md) / col
+
+# Function: col()
+
+```ts
+function col(name): Expr
+```
+
+Reference a column by its exact, case-sensitive name.
+
+## Parameters
+
+* **name**: `string`
+
+## Returns
+
+[`Expr`](../classes/Expr.md)

docs/src/js/functions/func.md

@@ -0,0 +1,23 @@
+[**@lancedb/lancedb**](../README.md) • **Docs**
+
+***
+
+[@lancedb/lancedb](../globals.md) / func
+
+# Function: func()
+
+```ts
+function func(name, ...args): Expr
+```
+
+Call a registered SQL function, such as `func("lower", col("firstName"))`.
+
+## Parameters
+
+* **name**: `string`
+
+* ...**args**: [`ExprLike`](../type-aliases/ExprLike.md)[]
+
+## Returns
+
+[`Expr`](../classes/Expr.md)

docs/src/js/functions/lit.md

@@ -0,0 +1,21 @@
+[**@lancedb/lancedb**](../README.md) • **Docs**
+
+***
+
+[@lancedb/lancedb](../globals.md) / lit
+
+# Function: lit()
+
+```ts
+function lit(value): Expr
+```
+
+Create a string or numeric literal. Unsafe integers are represented as Float64.
+
+## Parameters
+
+* **value**: `string` \| `number`
+
+## Returns
+
+[`Expr`](../classes/Expr.md)

docs/src/js/functions/litBool.md

@@ -0,0 +1,21 @@
+[**@lancedb/lancedb**](../README.md) • **Docs**
+
+***
+
+[@lancedb/lancedb](../globals.md) / litBool
+
+# Function: litBool()
+
+```ts
+function litBool(value): Expr
+```
+
+Create a boolean literal.
+
+## Parameters
+
+* **value**: `boolean`
+
+## Returns
+
+[`Expr`](../classes/Expr.md)

docs/src/js/functions/litInt.md

@@ -0,0 +1,21 @@
+[**@lancedb/lancedb**](../README.md) • **Docs**
+
+***
+
+[@lancedb/lancedb](../globals.md) / litInt
+
+# Function: litInt()
+
+```ts
+function litInt(value): Expr
+```
+
+Create an Int64 literal from a JavaScript safe integer. Other numbers throw RangeError.
+
+## Parameters
+
+* **value**: `number`
+
+## Returns
+
+[`Expr`](../classes/Expr.md)

docs/src/js/globals.md

@@ -28,6 +28,7 @@
 - [Catalog](classes/Catalog.md)
 - [Connection](classes/Connection.md)
 - [DatabaseNames](classes/DatabaseNames.md)
+- [Expr](classes/Expr.md)
 - [HeaderProvider](classes/HeaderProvider.md)
 - [Index](classes/Index.md)
 - [Job](classes/Job.md)
@@ -165,6 +166,7 @@
 - [Data](type-aliases/Data.md)
 - [DataLike](type-aliases/DataLike.md)
 - [DataTypeLike](type-aliases/DataTypeLike.md)
+- [ExprLike](type-aliases/ExprLike.md)
 - [FieldLike](type-aliases/FieldLike.md)
 - [IntoSql](type-aliases/IntoSql.md)
 - [IntoVector](type-aliases/IntoVector.md)
@@ -179,11 +181,16 @@
 
 - [RecordBatchIterator](functions/RecordBatchIterator.md)
 - [blob](functions/blob.md)
+- [col](functions/col.md)
 - [connect](functions/connect.md)
 - [connectCatalog](functions/connectCatalog.md)
 - [connectNamespace](functions/connectNamespace.md)
+- [func](functions/func.md)
 - [instrumentLanceDbMetrics](functions/instrumentLanceDbMetrics.md)
 - [isBlobField](functions/isBlobField.md)
+- [lit](functions/lit.md)
+- [litBool](functions/litBool.md)
+- [litInt](functions/litInt.md)
 - [makeArrowTable](functions/makeArrowTable.md)
 - [makeJsonField](functions/makeJsonField.md)
 - [packBits](functions/packBits.md)

docs/src/js/type-aliases/ExprLike.md

@@ -0,0 +1,13 @@
+[**@lancedb/lancedb**](../README.md) • **Docs**
+
+***
+
+[@lancedb/lancedb](../globals.md) / ExprLike
+
+# Type Alias: ExprLike
+
+```ts
+type ExprLike: Expr | string | number | boolean;
+```
+
+Values accepted by expression operators.