fix: capturing with a configureScope callback no longer re-runs BeforeBreadcrumb or re-syncs the scope to native SDKs

[jamescrosswell]

Summary

Scope.Clone() copied data into the new scope through the public mutators (AddBreadcrumb, SetTag, User, Environment, ...). Every clone therefore:

• re-ran BeforeBreadcrumb on breadcrumbs it had already processed. This affects every platform, not only scope sync: with a transforming callback, CaptureException(ex, s => ...) sent crumb [scrubbed] [scrubbed] where CaptureException(ex) sent crumb [scrubbed]
• re-applied TagFilters
• re-sent the whole scope (breadcrumbs, tags, extras, user one property at a time, environment, trace) to the scope observer. On MAUI this duplicated breadcrumbs on the native scope on every CaptureException(ex, configureScope), and in non-global mode on every PushScope

Clone() now fills in the new scope with scope sync turned off, and copies breadcrumbs and tags directly so BeforeBreadcrumb and TagFilters don't run again.

Separately, the temporary scope handed to configureScope in CaptureEvent/CaptureFeedback no longer syncs to the scope observer. That scope only exists for a single event, but tags, users and breadcrumbs set on it were synced to the native scope and stayed there, ending up on later native crashes.

Notes for review

• The second change answers the open question in the issue. Managed events are sent by the managed transport on every platform, so the native scope doesn't need per-event data. It's easy to drop if we'd rather not: two lines in Hub and the two *_ConfigureScope_ChangesNotSynced tests.
• Both changes use a new internal Scope.ScopeSyncEnabled flag. The ten observer calls in Scope now go through a single private ScopeObserver accessor that checks it, instead of each checking Options.EnableScopeSync.
• In non-global mode, the first PushScope() in the Hub constructor used to send the root trace to the scope observer as a side effect of cloning. The Hub constructor now does that explicitly, so native crashes stay on the same trace as managed errors. Global mode (iOS/Android) never had this sync and is unchanged.
• SdkVersion.CopyTo is shared by Apply and Clone.
• Apply(Scope) is public and unchanged: applying one scope onto another still goes through the mutators.

Closes #5647

🤖 Generated with Claude Code

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 75.05%. Comparing base (70909e9) to head (6ad6152).
⚠️ Report is 8 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #5653      +/-   ##
==========================================
+ Coverage   74.94%   75.05%   +0.11%     
==========================================
  Files         515      515              
  Lines       18975    18990      +15     
  Branches     3695     3692       -3     
==========================================
+ Hits        14220    14253      +33     
+ Misses       3875     3869       -6     
+ Partials      880      868      -12     

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[ric-oliv]

Nice! I've added a couple of edge cases as inline comments, but the rest looks great!

[ric-oliv]

Nice!