Remove unnecessary .trimEnd() and fix facet detection (#3672)

* Fix link facet detection

Exclude the trailing period from the link, similar as done in the atproto package

* Fix JSON to text conversion

The trimEnd() call was only needed because we were always appending \n\n at the end. Fix that by only adding line breaks after non-final paragraphs.

* Detect paste reliably

---------

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

src/view/com/composer/text-input/web/LinkDecorator.ts

@@ -14,11 +14,11 @@
  * the facet-set.
  */
 
-import {Mark} from '@tiptap/core'
-import {Plugin, PluginKey} from '@tiptap/pm/state'
-import {Node as ProsemirrorNode} from '@tiptap/pm/model'
-import {Decoration, DecorationSet} from '@tiptap/pm/view'
 import {URL_REGEX} from '@atproto/api'
+import {Mark} from '@tiptap/core'
+import {Node as ProsemirrorNode} from '@tiptap/pm/model'
+import {Plugin, PluginKey} from '@tiptap/pm/state'
+import {Decoration, DecorationSet} from '@tiptap/pm/view'
 
 import {isValidDomain} from 'lib/strings/url-helpers'
 
@@ -91,7 +91,7 @@ function iterateUris(str: string, cb: (from: number, to: number) => void) {
       uri = `https://${uri}`
     }
     let from = str.indexOf(match[2], match.index)
-    let to = from + match[2].length + 1
+    let to = from + match[2].length
     // strip ending puncuation
     if (/[.,;!?]$/.test(uri)) {
       uri = uri.slice(0, -1)