[Embeds] Embed subdomain landing page (#3501)

* add build output to web build

* simplify post-build step by copying everything at once

* make script that converts placeholder -> iframe

* dynamically resize iframe based on inner content

Requires the iframe content to `postMessage` its height back up to the parent

* add lang to embed

* svg explicit height -> viewBox

* add build output to web build

* simplify post-build step by copying everything at once

* attempt to fix go embed issue

* rm changes to bskyweb

* remove another bskyweb change

* embed landing page

* Drop xl breakpoint, too far down

* Remove pointer enter behavior

* Avoid button width jump

* Escape HTML

---------

Co-authored-by: Dan Abramov <dan.abramov@gmail.com>

bskyembed/src/main.tsx

@@ -1,88 +0,0 @@
-import './index.css'
-
-import {AppBskyFeedDefs, BskyAgent} from '@atproto/api'
-import {h, render} from 'preact'
-
-import logo from '../assets/logo.svg'
-import {Container} from './container'
-import {Link} from './link'
-import {Post} from './post'
-import {getRkey} from './utils'
-
-const root = document.getElementById('app')
-if (!root) throw new Error('No root element')
-
-const searchParams = new URLSearchParams(window.location.search)
-
-const agent = new BskyAgent({
-  service: 'https://public.api.bsky.app',
-})
-
-const uri = searchParams.get('uri')
-
-if (!uri) {
-  throw new Error('No uri in query string')
-}
-
-agent
-  .getPostThread({
-    uri,
-    depth: 0,
-    parentHeight: 0,
-  })
-  .then(({data}) => {
-    if (!AppBskyFeedDefs.isThreadViewPost(data.thread)) {
-      throw new Error('Expected a ThreadViewPost')
-    }
-    const pwiOptOut = !!data.thread.post.author.labels?.find(
-      label => label.val === '!no-unauthenticated',
-    )
-    if (pwiOptOut) {
-      render(<PwiOptOut thread={data.thread} />, root)
-    } else {
-      render(<Post thread={data.thread} />, root)
-    }
-  })
-  .catch(err => {
-    console.error(err)
-    render(<ErrorMessage />, root)
-  })
-
-function PwiOptOut({thread}: {thread: AppBskyFeedDefs.ThreadViewPost}) {
-  const href = `/profile/${thread.post.author.did}/post/${getRkey(thread.post)}`
-  return (
-    <Container href={href}>
-      <Link
-        href={href}
-        className="transition-transform hover:scale-110 absolute top-4 right-4">
-        <img src={logo as string} className="h-6" />
-      </Link>
-      <div className="w-full py-12 gap-4 flex flex-col items-center">
-        <p className="max-w-80 text-center w-full text-textLight">
-          The author of this post has requested their posts not be displayed on
-          external sites.
-        </p>
-        <Link
-          href={href}
-          className="max-w-80 rounded-lg bg-brand text-white color-white text-center py-1 px-4 w-full mx-auto">
-          View on Bluesky
-        </Link>
-      </div>
-    </Container>
-  )
-}
-
-function ErrorMessage() {
-  return (
-    <Container href="https://bsky.app/">
-      <Link
-        href="https://bsky.app/"
-        className="transition-transform hover:scale-110 absolute top-4 right-4">
-        <img src={logo as string} className="h-6" />
-      </Link>
-      <p className="my-16 text-center w-full text-textLight">
-        Post not found, it may have been deleted.
-      </p>
-    </Container>
-  )
-}