feat(photos): downloaded media also lands in a "Connect" album in Photos

The Files folder is the app's own copy — it powers offline playback and Manage
storage — but Files is not where anyone looks for photos and videos. The Photos app
is, and only PhotoKit can write there; @capacitor/filesystem cannot, because an
app sandbox and the photo library are separate stores. So this adds a small native
plugin, mirroring the existing audio-route one.

- mobile/plugins/media-library: saveToAlbum({path, album, kind}) finds or creates
  the album and adds the asset. Uses addResource(with:fileURL:), which is uniform
  for photo and video and non-optional, unlike creationRequestForAssetFrom*, which
  can silently no-op.
- Requests .readWrite, NOT .addOnly: addOnly can add an asset but cannot look up or
  create an ALBUM, which is the whole point here. Both photo-library usage strings
  are already set by ios-patch.sh.
- If the album can't be resolved (e.g. "limited" access), the asset is still saved
  to the camera roll — landing somewhere beats failing outright. A racing create
  from two simultaneous downloads re-looks-up instead of erroring.
- Podspec named MediaLibrary.podspec with s.name = 'MediaLibrary' to match
  PascalCase of the package name — the same trap that broke the AudioRoute build.
  Checked by a script: pod name, jsName and declared-vs-implemented methods.

Entirely best-effort from the web side: a denied permission or an older app build
never fails a download that is already safe in the app folder. Added a Settings
toggle since this does keep a second copy of the file.

Needs a new iOS build — new native plugin.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

mobile/plugins/media-library/MediaLibrary.podspec

@@ -0,0 +1,22 @@
+require 'json'
+
+package = JSON.parse(File.read(File.join(__dir__, 'package.json')))
+
+Pod::Spec.new do |s|
+  # NOTE: the pod name MUST be 'MediaLibrary' (PascalCase of the npm package name 'media-library').
+  # `cap sync` writes `pod 'MediaLibrary', :path => '../../plugins/media-library'` into the generated
+  # Podfile, and CocoaPods then looks for a file literally named MediaLibrary.podspec whose s.name is
+  # 'MediaLibrary'. Any other name → "No podspec found for `MediaLibrary`" and pod install fails.
+  # (Same trap that broke the AudioRoute build — see mobile/plugins/audio-route/AudioRoute.podspec.)
+  s.name = 'MediaLibrary'
+  s.version = package['version']
+  s.summary = package['description']
+  s.license = package['license']
+  s.homepage = 'https://bizgaze.com'
+  s.author = 'BizGaze'
+  s.source = { :git => 'https://bizgaze.com/media-library.git', :tag => s.version.to_s }
+  s.source_files = 'ios/Sources/**/*.{swift,h,m}'
+  s.ios.deployment_target = '14.0'
+  s.dependency 'Capacitor'
+  s.swift_version = '5.1'
+end