feat: add independent CLI launches and preserve shared video bookmarks

Sources/App/PlaybackProgress.swift

@@ -2,28 +2,34 @@ import Foundation
 
 struct PlaybackProgress {
     private let defaults: UserDefaults
-    private var positions: [String: Double]
 
     init(defaults: UserDefaults = .standard) {
         self.defaults = defaults
-        positions = defaults.dictionary(forKey: "playbackPositions") as? [String: Double] ?? [:]
+        // Migrate the old shared dictionary once; separate keys prevent cross-player lost updates.
+        if let positions = defaults.dictionary(forKey: "playbackPositions") as? [String: Double] {
+            for (identity, position) in positions where position.isFinite && position > 0 {
+                let key = "playbackPosition:" + identity
+                if defaults.object(forKey: key) == nil { defaults.set(position, forKey: key) }
+            }
+            defaults.removeObject(forKey: "playbackPositions")
+        }
     }
 
     func position(for url: URL) -> Double? {
-        guard let position = positions[key(for: url)], position.isFinite, position > 0 else { return nil }
+        guard let position = defaults.object(forKey: key(for: url)) as? Double,
+              position.isFinite, position > 0 else { return nil }
         return position
     }
 
-    mutating func save(_ position: Double?, for url: URL) {
+    func save(_ position: Double?, for url: URL) {
         let key = key(for: url)
         let position = position.flatMap { $0.isFinite && $0 > 0 ? $0 : nil }
-        guard positions[key] != position else { return }
-        positions[key] = position
-        defaults.set(positions, forKey: "playbackPositions")
+        guard (defaults.object(forKey: key) as? Double) != position else { return }
+        defaults.set(position, forKey: key)
     }
 
     private func key(for url: URL) -> String {
         // YouTube callers supply the canonical webpage URL, never an expiring media URL.
-        return url.isFileURL ? url.standardizedFileURL.resolvingSymlinksInPath().absoluteString : url.absoluteString
+        return "playbackPosition:" + (url.isFileURL ? url.standardizedFileURL.resolvingSymlinksInPath().absoluteString : url.absoluteString)
     }
 }