feat(oxc-reference): add primitive literal candidate

[swernerx]

Summary

• add an internal versioned Rust-owned primitive/literal semantic candidate over the immutable schema-v1 Go-produced graph
• emit the candidate through the existing OXC attachment and graph-inspection path with response-local TypeIDs, all five root views, structured primitive/literal/union records, and explicit complete/truncated/unsupported/error states
• add a shared canonical Go/Rust fixture covering booleans, strings, numbers, bigint, null-like values, literal unions, and unsupported/truncated forms
• document the boundary in ADR-0017 and update the RFC/migration notes without changing producer authority or protocol

Semantic boundary

TypeScript 7's Go checker remains the semantic oracle. This PR does not change the TS7 producer protocol, add a producer capability, establish an independent Rust producer, or claim replacement readiness.

Validation

• cargo fmt --manifest-path internal/oxc_reference/Cargo.toml --all -- --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 — 11 passed
• go test -count=1 ./internal/semanticfacts ./internal/tsfacts ./cmd/tsfacts — all 3 packages passed
• go build -tags=noembed -o /tmp/tsfacts-issue40 ./cmd/tsfacts
• go test -count=1 ./... — passed
• npx hereby lint — 0 issues in the root module and _tools
• npx hereby check:format — passed
• git diff --cached --check — passed

Closes #40