[takeokunn]

Scope

• Port the VM's standalone object helpers to the JavaScript runtime and register the implementation and regression tests in the ASDF systems. This PR adds definitions and tests; it does not add JavaScript call sites.
• Retain the existing transition-table and parent-shape fields without adding consumers. value-type-def-total-size counts declared fields, and the mark-word API currently exposes only GC-color extraction.
• Keep cl-cc-vm/src/interop/v8-objects-133.lisp until this change is merged to cl-cc-javascript/main and that main commit's nix flake check succeeds. The VM phase then removes its copy.

Verification

The flake declares only x86_64-linux, so I ran its six checks individually on Darwin with pinned tools and dependency roots. The full nix flake check remains the CI gate.

• timeout --kill-after=30 900 sbcl --script run-tests.lisp with pinned source roots and TZDIR: 1,109 passed; 0 skipped, failed, or errored.
• timeout --kill-after=30 600 sbcl --script scripts/run-compile-check.lisp: passed.
• python3 scripts/check-orphan-tests.py --root . --sbcl <pinned-SBCL> --allowlist t/orphan-test-allowlist.tsv: 35 found, 31 registered, 4 allowlisted, 0 orphaned.
• Pinned formatter: nixfmt --check flake.nix; one Nix input, passed.
• Pinned MkDocs and Material: mkdocs build --strict --config-file docs/mkdocs.yml --site-dir <temp>/site; passed, 56 files generated.
• timeout --kill-after=30 900 sbcl --script scripts/run-coverage.lisp: 1,109 passed. test -f coverage-report/cover-index.html passed; the report contains 851 files.

The coverage runner could not export LCOV because SB-COVER reported NIL is not of type VECTOR. The flake coverage check gates only on the HTML index.