Make a generic TypeScript function for property/field mapping

I want to convert an array of objects, into a set of known properties of a single object. I have working TypeScript code, but I want to make it into a generic function. Below is my working code.

global definition...

export type Pic = SanityDocument & {
    id: Slug,
    caption: string,
    group: string,
    pic: Image,
}

Example code I want to make generic:

const pics : Pic[]  = await sanityClient.fetch(`
        *[_type == "pic"]
    `);

// Example type I want to make generic...
type PicMap = {alpha: Pic, bravo: Pic};

// How do I make `PicMap` be a generic I specify
// as part of a function call?
const picMap : PicMap = pics.reduce((acc, pic : Pic) => {
  acc[pic.id.current as keyof PicMap] = pic;
  return acc;
}, {} as PicMap);

The above code works. I want to modify the above code so that type PicMap becomes generic, so I can re-use this code for other target objects. How is that done? There are three scenarios of what I'm looking for:

1. A TypeScript function that allows me to generically replace PicMap with something else. However, the Pic type is fixed/required. This is my minimum requirement.
2. As before, but the Pic type is also generic.
3. A variant of either option #1 or #2, where the PicMap type can be declared inline rather than requiring an explicit declaration.

Option #1 is what I absolutely need to fulfill this question. Options #2 and/or #3 are icing on the cake.

I am intentionally not using Record<t,k> for two reasons. First, I want the picMap object properties accessible with auto-complete. Second, for me it is ok if the source array has objects that don't exist as exposed properties of the final object. In other words, I am not attempting to limit what properties can be assigned...I am only limiting which properties I can "see" with intellisense. So I don't want a solution like this.

UPDATE

My own attempt at a solution currently looks like this:

New global definition...

type NamedAsset = SanityDocument & {
    id: Slug // has a string property called 'current'
}

And then my generic function...

export function MapAsset<
   V extends object, 
   K extends NamedAsset, 
   T extends K[]> (items:T) : V {
    const acc = items.reduce((acc, asset:K) => {
        acc[asset.id.current as keyof V] = asset;
        return acc;
    }, {} as V);
    return acc;
}

Unfortunately the above has a "Type 'K' is not assignable" error. However, if the above were working then my example usage might look like this:

// Sample type for array contents...
export type Pic = NamedAsset & {
    caption: string,
    group: string,
    pic: Image,
}

// Just some arbitrary way to fill the array.
const pics : Pic[]  = await sanityClient.fetch(`
        *[_type == "pic"]
    `);

// An arbitrary type of arbitrary declared properties.
type PicMap = {alpha: Pic, bravo: Pic};

const picMap : PicMap = MapAsset(pics);
// Or, alternatively...
const picMap = MapAsset<PicMap>(pics);

UPDATE #2

I asked ChatGPT to solve the error I found in my prior example solution. What it gave back does work, but it is brain-melting. It's solution:

export function MapAsset<T extends NamedAsset[]>(items:T):
{
    [K in T[number]['id']['current']]: Extract<T[number], {id : {current:K}}>
}
{
    const acc = items.reduce((acc, asset) => {
        acc[asset.id.current] = asset;
        return acc;
    }, {} as any);
    return acc;
}

Then to use the above, I do this:

type PicMap = {alpha: Pic, bravo: Pic};
const picMap = MapAsset(pics) as PicMap;

Having a function whose result I must cast is not what I had in mind. However, I admit this would be acceptable-ish in the absence of a better answer. Aside from the need to cast the result, I also don't like that the MapAsset function is surprisingly esoteric.