fix ios opml import

[Tlaster]

fix #1938

[Copilot]

Pull request overview

Fixes iPadOS OPML import/opening by properly registering an OPML Uniform Type Identifier (UTI) and using it consistently in the SwiftUI file importer/exporter flow.

Changes:

• Define and use a custom UTType.opml (dev.dimension.flare.opml) for OPML files.
• Update the OPML FileDocument readable content types to rely on the custom UTI.
• Register OPML in Info.plist via UTExportedTypeDeclarations and CFBundleDocumentTypes so iOS can recognize .opml files.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated no comments.

File	Description
iosApp/flare/UI/Screen/RssScreen.swift	Switches file importer allowed types to include the new .opml UTType.
iosApp/flare/Info.plist	Adds document type + exported UTI declaration for dev.dimension.flare.opml (extension/mime mapping).
iosApp/flare/Common/OPMLFile.swift	Introduces UTType.opml and updates OPMLFile to use it for reading/exporting.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.