add sqlite_vec extension, updates !93

# Changelog

 - 2026-03-17 v1.47.0: Add CGO-free version of the vector extensions from https://github.com/asg017/sqlite-vec. See `vec_test.go` for example usage. From the GitHub project page:

  - **Important:** sqlite-vec is a pre-v1, so expect breaking changes!

  - Store and query float, int8, and binary vectors in vec0 virtual tables

  - Written in pure C, no dependencies, runs anywhere SQLite runs (Linux/MacOS/Windows, in the browser with WASM, Raspberry Pis, etc.)

  - Store non-vector data in metadata, auxiliary, or partition key columns

 - 2026-03-16 v1.46.2: Upgrade to  [SQLite 3.51.3](https://sqlite.org/releaselog/3_51_3.html).

 - 2026-02-17 v1.46.1:

	go test -v -timeout 24h

vendor:

	cd vendor_libsqlite3 && go build -o ../vendor main.go

	cd vendor_libs && go build -o ../vendor main.go

	./vendor

	rm -f vendor

	make build_all_targets

// Copyright 2026 The Sqlite Authors. All rights reserved.

// Use of this source code is governed by a BSD-style

// license that can be found in the LICENSE file.

package vec

import (

	"modernc.org/libc"

)

func ___inline_isnanf(tls *libc.TLS, f float32) int32 {

	return libc.X__inline_isnanf(tls, f)

}

func ___inline_isnan(tls *libc.TLS, f float64) int32 {

	return libc.X__inline_isnand(tls, f)

}