[fix] Assistant websearch text/markdown source

[mishig25]

Description

When you combine assistant websearch with TEI, there was an error. (However, it was/is working fine with local models through transformers.js).

Although we have

chat-ui/src/lib/server/embeddingEndpoints/tei/embeddingEndpoints.ts

Line 63 in b2bee62

body: JSON.stringify({ inputs: batchInputs, normalize: true, truncate: true }),

, there was still an error (i.e. TEI endpoint was rejecting the input citing it as invalid json) when a text value was a text concat value (i.e. rather than "Hello World", the actual value was "Hello " + "World"). Therefore, we needed to add

chat-ui/src/lib/server/websearch/parseWeb.ts

Lines 35 to 37 in b2bee62

	const text = await r.text();
	// JSON.stringify is needed to turn string concatenation into a single string (ex: "Hello, " + "world!" -> "Hello, world!")
	return JSON.stringify(text);

on main

this PR

[coyotte508]

> JSON.stringify('"Hello, " + "world!"')
'"\\"Hello, \\" + \\"world!\\""'

It doesn't give "Hello, world!"

Not sure I understand where the concat happens

[mishig25]

example:

const text = await r.text();
console.log({text})
// {text: "Hello " + "world"}

and TEI endpoint was failing with Invalid json

let text = r.text();
text = JSON.stringify(text)
console.log({text})
// {text: "Hello world"}

TEI endpoint works fine

[coyotte508]

will let @nsarrazin review I don't understand it

[nsarrazin]

Tested locally, seems to fix the issue