feat: add context/libc Stage 4 helper APIs

[buke]

• add DumpError, LoopOnce, PollIO, NewDate, NewSymbol, NewGlobalSymbol
• add SetImportMeta and BootstrapBJSON context helpers
• add Value.IsDate
• add comprehensive Stage 4 tests with fail-closed coverage

[gemini-code-assist]

Code Review

This pull request introduces several new methods to the Context and Value types to support JavaScript Dates, Symbols, and module metadata. It also adds event loop control helpers like LoopOnce and PollIO, along with a BootstrapBJSON utility. The review feedback recommends refactoring BootstrapBJSON from a standalone function into a method of the Context type to ensure consistency with the library's existing API patterns.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 100.00%. Comparing base (00c83bc) to head (bba597b).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff            @@
##              main      #737   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files           17        17           
  Lines         3659      3704   +45     
=========================================
+ Hits          3659      3704   +45     

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

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[buke]

/gemini review

[gemini-code-assist]

Code Review

This pull request introduces several new methods to the Context and Value types to support JavaScript Date, Symbols, and module metadata. It also refactors the BootstrapStdOS and BootstrapTimers functions into methods on the Context type and adds event loop helpers like LoopOnce and PollIO. Feedback was provided to simplify redundant nil checks in the SetImportMeta and BootstrapBJSON methods where internal helper functions already perform these validations.

[buke]

/gemini review

[gemini-code-assist]

Code Review

This pull request introduces several new helper methods to the Context and Value types, including support for JavaScript Dates, Symbols, and BJSON bootstrapping. It also adds event loop control methods like LoopOnce and PollIO, along with comprehensive tests for these new features. Feedback was provided regarding the refactoring of BootstrapStdOS and BootstrapTimers from standalone functions to methods on *Context, which introduces breaking changes to the public API. It is recommended to maintain backward compatibility by providing deprecated standalone wrappers for these functions.