Compile VarRef-free query patterns

[MesTTo]

Summary

Adds a compiled matcher path for query patterns that contain no VarRef.

The compiler lowers each pattern factor into preorder MatchOps and query_multi_raw executes that program directly. Patterns with query-side VarRef still use the existing coreferential_transition interpreter.

This branch also adds focused tests for the compiler boundary and a public query_multi smoke test over real inserted atoms.

Reviewer Note

This is the small stage-1 matcher precompile. Later local compiled-matcher commits for query-side VarRef and compound captures are not included because they depend on broader matcher changes.

Local notes measured process_calculus at 26.1s to 25.6s. This branch should be reviewed as a narrow matcher slice, not the larger set-at-a-time emit work.

Validation

• RUSTFLAGS='-C target-cpu=native' cargo +nightly-2026-06-01 test -p mork --lib compile_match_program -- --nocapture
• RUSTFLAGS='-C target-cpu=native' cargo +nightly-2026-06-01 test -p mork --lib query_multi_matches_varref_free_pattern_with_compiled_program -- --nocapture
• RUSTFLAGS='-C target-cpu=native' cargo +nightly-2026-06-01 test -p mork --lib
• jscpd --reporters console --format rust --min-lines 8 --min-tokens 80 kernel/src/space.rs
• git diff --check