Summary

• mount read-only fs.FS WASI filesystems through a sysfs adapter instead of wazero's generic WithFSMount adapter
• preserve POSIX-style readlink behavior for existing non-symlink paths: return EINVAL instead of ENOSYS
• add a WASI preview1 regression test covering path_readlink on a regular file from an in-memory mount

Validation

• go test ./engine -run TestWazeroEngine_FSMountReadlinkRegularFile -count=1
• go test ./wat
• built wippy runtime with a temporary go.work pointing at this branch
• installed real hub dependency wippy-langs/r@0.2.6 in packed .wapp mode without options.unpack_modules
• /tmp/wippy-r-demo-packed: wippy run -c -x app:r_format_probe passed normalizePath, stats::t.test, png/svg/pdf plots
• /tmp/wippy-r-demo-packed: wippy run test passed 2/2
• generated /tmp/wippy-r-demo-packed/scratch/plot.png: valid 800x600 PNG

Note

• go test ./engine currently fails on origin/main and this branch in TestMemoryReleaseOnClose with the same heap-growth assertion; this is baseline debt and unrelated to this patch.