[codex] Cache tagged-template objects per call site

[andrewtdiz]

Closes #2855.

Summary

• assign stable HIR call-site ids to tagged template sites and route codegen through a runtime template-object cache
• freeze cooked/raw template arrays, install non-enumerable immutable .raw, and guard array mutation paths against frozen template objects
• add a focused Node parity fixture for call-site identity, .raw, frozen/extensible state, and mutation resistance

Validation

• cargo fmt --all -- --check
• git diff --check origin/main..HEAD
• ./scripts/check_file_size.sh
• CARGO_TARGET_DIR=/root/perry-worktrees/perry-runtime-tagged-template-cache/target cargo check -p perry-hir -p perry-codegen -p perry-runtime
• CARGO_TARGET_DIR=/root/perry-worktrees/perry-runtime-tagged-template-cache/target npm exec --package=node@25 -- bash -lc 'node --version; ./run_parity_tests.sh --suite node-suite --module globals --filter tagged-template-cache-freeze'\n