feat(oxc-reference): produce primitive literals independently

[swernerx]

Summary

• derive primitive, literal, null-like, literal-union, and contextual-literal records independently from project source and OXC semantic nodes
• own response-local Rust type identity, five TypeFacts roots, recovery, unsupported, and budget/truncation states without consuming the Go graph
• upgrade the shadow conformance gate to compare exact OXC mapping, structured semantics, and a response-wide Go↔Rust TypeID bijection at a 15-record / 1,000,000 ppm threshold
• add the shared recovery/primitive/literal corpus slice and ADR-0019

Migration boundary

• Go remains the semantic authority and production fallback
• the Rust implementation remains shadow-only
• no TS7 producer protocol or external consumer changes
• no Palamedes changes

Validation

• cargo fmt --all --manifest-path internal/oxc_reference/Cargo.toml -- --check
• cargo clippy --locked --manifest-path internal/oxc_reference/Cargo.toml --all-targets -- -D warnings
• cargo test --locked --manifest-path internal/oxc_reference/Cargo.toml (15 passed)
• two byte-identical run-conformance.sh runs: 15/15 supported records, 1,000,000 ppm, 50/50 root identity matches, 11/11 OXC mappings, zero blocking differences
• go test -count=1 ./internal/semanticfacts ./internal/tsfacts ./cmd/tsfacts
• go build -tags=noembed ./cmd/tsfacts
• npx hereby lint
• npx hereby check:format
• full go test -count=1 ./...: all packages passed except the local macOS internal/fswatch FSEvents backend, which missed kernel events after retries; the same package passed completely with its kqueue backend

Closes #45