feat(ios): improve share preview (#15538)

#### PR Dependency Tree

* **PR #15538** 👈

This tree was auto-generated by
[Charcoal](https://github.com/danerwilliams/charcoal)

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit

* **New Features**
* Added rich link previews to mobile and iOS sharing, including images,
metadata, transcripts, and selected text.
* Share imports can now create structured content blocks, embeds,
bookmarks, and transcript callouts.
* Added workspace-aware preview handling for cloud, self-hosted, and
signed-out modes.
* **Accessibility**
* Improved collapse/expand controls with semantic buttons and ARIA
relationships.
* **Bug Fixes**
  * Enhanced URL and error sanitization in server logs.
* Improved link-preview CORS support, validation, and request handling.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

packages/frontend/apps/ios/App/Shared/ShareInbox/ShareInboxModels.swift

@@ -36,6 +36,7 @@ struct ShareInboxItem: Codable, Equatable, Identifiable {
   var createdAt: Date
   var title: String
   var content: ShareInboxContent
+  var previewRoute: SharePreviewRoute?
   var target: ShareInboxTarget?
   var previewText: String?
   var attachments: [ShareInboxAttachment]
@@ -48,6 +49,7 @@ struct ShareInboxItem: Codable, Equatable, Identifiable {
     createdAt: Date = Date(),
     title: String,
     content: ShareInboxContent,
+    previewRoute: SharePreviewRoute? = nil,
     target: ShareInboxTarget? = nil,
     previewText: String? = nil,
     attachments: [ShareInboxAttachment] = [],
@@ -59,6 +61,7 @@ struct ShareInboxItem: Codable, Equatable, Identifiable {
     self.createdAt = createdAt
     self.title = title
     self.content = content
+    self.previewRoute = previewRoute
     self.target = target
     self.previewText = previewText
     self.attachments = attachments