feat(runtime): align raw context AToB intrinsic

[buke]

• add an AToB option to raw-context intrinsic selection
• wire JS_AddIntrinsicAToB into applyIntrinsics and AllIntrinsics
• cover raw-context AToB behavior and failure hooks in runtime tests

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 100.00%. Comparing base (f04fc26) to head (c434927).

Additional details and impacted files

@@            Coverage Diff            @@
##              main      #743   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files           17        17           
  Lines         3705      3709    +4     
=========================================
+ Hits          3705      3709    +4     

Files with missing lines	Coverage Δ
runtime.go	100.00% <100.00%> (ø)

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[gemini-code-assist]

Code Review

This pull request introduces support for atob and btoa intrinsics in the runtime. It adds an AToB option to the IntrinsicSet, provides a WithAToB configuration function, and updates the intrinsic application logic to include the new functionality. Comprehensive tests were added to verify the behavior of these intrinsics when enabled or disabled, including error handling scenarios. I have no feedback to provide.