Add first-class Windows support

[DeanoC]

Summary

• add Windows runtime support across executable memory, guard pages, JIT, cache paths, and WASI host integration
• make the spec, e2e, and real-world test runners cross-platform and add Windows CI coverage, release packaging, and PowerShell install support
• support guest path aliases for preopened directories so Windows real-world WASI compat tests use stable guest-visible mount points

Testing

• fork CI passed on Linux, macOS, and Windows in Add first-class Windows support DeanoC/zwasm#1
• local Windows verification for the final compat fix: rust_file_io under zwasm.exe and wasmtime.exe with --dir HOST::/sandbox both returned 0 with matching output

Notes

• this PR is a cleaned squash of the implementation/debugging work from the fork validation PR: Add first-class Windows support DeanoC/zwasm#1