CmdPal: Migrate bookmarks manually (#42814)

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fix/what does it change/how was it tested (even manually, if necessary)?
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## Summary of the Pull Request

This PR fixes the migration of bookmarks from versions prior to 0.95,
resolving an issue where hotkeys and aliases wouldn’t persist on
bookmarks created with Command Palette 0.94 or earlier.

It removes ID auto-fixing from `BookmarkData` in favor of an explicit
migration step handled by `BookmarkManager`.

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## PR Checklist

- [x] Closes: #42796
- [ ] **Communication:** I've discussed this with core contributors
already. If the work hasn't been agreed, this work might be rejected
- [ ] **Tests:** Added/updated and all pass
- [ ] **Localization:** All end-user-facing strings can be localized
- [ ] **Dev docs:** Added/updated
- [ ] **New binaries:** Added on the required places
- [ ] [JSON for
signing](https://github.com/microsoft/PowerToys/blob/main/.pipelines/ESRPSigning_core.json)
for new binaries
- [ ] [WXS for
installer](https://github.com/microsoft/PowerToys/blob/main/installer/PowerToysSetup/Product.wxs)
for new binaries and localization folder
- [ ] [YML for CI
pipeline](https://github.com/microsoft/PowerToys/blob/main/.pipelines/ci/templates/build-powertoys-steps.yml)
for new test projects
- [ ] [YML for signed
pipeline](https://github.com/microsoft/PowerToys/blob/main/.pipelines/release.yml)
- [ ] **Documentation updated:** If checked, please file a pull request
on [our docs
repo](https://github.com/MicrosoftDocs/windows-uwp/tree/docs/hub/powertoys)
and link it here: #xxx

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or any additional comments/features here -->
## Detailed Description of the Pull Request / Additional comments

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wherever possible, but list manual validation steps taken as well -->
## Validation Steps Performed

src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.Bookmark/BookmarksManager.cs

@@ -103,7 +103,33 @@ internal sealed partial class BookmarksManager : IDisposable, IBookmarksManager
         try
         {
             var jsonData = _dataSource.GetBookmarkData();
-            _bookmarksData = _parser.ParseBookmarks(jsonData);
+            var bookmarksData = _parser.ParseBookmarks(jsonData);
+
+            // Upgrade old bookmarks if necessary
+            // Pre .95 versions did not assign IDs to bookmarks
+            var upgraded = false;
+            for (var index = 0; index < bookmarksData.Data.Count; index++)
+            {
+                var bookmark = bookmarksData.Data[index];
+                if (bookmark.Id == Guid.Empty)
+                {
+                    bookmarksData.Data[index] = bookmark with { Id = Guid.NewGuid() };
+                    upgraded = true;
+                }
+            }
+
+            lock (_lock)
+            {
+                _bookmarksData = bookmarksData;
+            }
+
+            // LOAD BEARING: Save upgraded data back to file
+            // This ensures that old bookmarks are not repeatedly upgraded on each load,
+            // as the hotkeys and aliases are tied to the generated bookmark IDs.
+            if (upgraded)
+            {
+                _ = SaveChangesAsync();
+            }
         }
         catch (Exception ex)
         {

src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.Bookmark/Persistence/BookmarkData.cs

@@ -19,7 +19,7 @@ public sealed record BookmarkData
     [SetsRequiredMembers]
     public BookmarkData(Guid id, string? name, string? bookmark)
     {
-        Id = id == Guid.Empty ? Guid.NewGuid() : id;
+        Id = id;
         Name = name ?? string.Empty;
         Bookmark = bookmark ?? string.Empty;
     }