fix(binding): forward projected location writes

[Kyle-Ye]

Summary

• Write the updated base value through the underlying location with the original transaction.
• Add regression coverage for the stored value, unchanged fields, transaction forwarding, and exactly one underlying write.
• Update binding projection tests to check both the projected value and the underlying storage after writes.

Stack

Depends on #1048.

[tuist]

🛠️ Tuist Run Report 🛠️

Tests 🧪

Scheme	Status	Cache hit rate	Tests	Skipped	Ran	Commit
OpenSwiftUI	❌	0 %	1161	0	1161	2b1dde006

Failed Tests ❌

• OpenSwiftUI: 13 failed tests (View all)

• set() · OpenSwiftUICoreTests · ForceUnwrappingTests
  (unwrappedBinding.wrappedValue → 20) == 10

• setFromCGFloat() · OpenSwiftUICoreTests · ToDoubleTests
  (doubleBinding.wrappedValue → 2.71828).isApproximatelyEqual(to: 1.0)

• withString() · OpenSwiftUICoreTests · EqualsTests
  (resultBinding2.wrappedValue → true) == false

• setFromFloat() · OpenSwiftUICoreTests · ToDoubleTests
  (doubleBinding.wrappedValue → 2.5).isApproximatelyEqual(to: 1.0, absoluteTolerance: 0.001)

• set() · OpenSwiftUICoreTests · ToDoubleFromIntegerTests
  (doubleBinding.wrappedValue → 25.0) == 10.0

Showing 5 of 13 failed tests. See links above for full details.

Builds 🔨

Scheme	Status	Duration	Commit
OpenSwiftUI	✅	1m 41s	2b1dde006

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 17.13%. Comparing base (df0926b) to head (880a129).

Additional details and impacted files

@@                       Coverage Diff                       @@
##           codex/stored-location-tests    #1049      +/-   ##
===============================================================
+ Coverage                        17.10%   17.13%   +0.02%     
===============================================================
  Files                              735      735              
  Lines                            53936    53937       +1     
===============================================================
+ Hits                              9226     9242      +16     
+ Misses                           44710    44695      -15     

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