Reference evaluator round 2: ledger 198 to 88, bytes reference semantics, normative json parser, vendored libm

[O6lvl4]

Second stdlib burn-down round for the judge-owned reference evaluator (#10).

Measured (local, full corpus)

• 610 programs: 522 evaluated, 518 agree with native, 0 evaluator faults
• the 4 disagreements are all adjudicated under @ref-allow (F1 named-arg order; F10 ±0 min/max lag ×3 — float_sign_minmax_ieee newly carries the directive, same retired tie rule)
• abstain ledger 198 → 88 in 35 classes (shrink-only ratchet tightens)
• λ_almd kernel 49/49 byte-identical ×2; independence + clippy walls hold; fmt oracle 2/2

What landed

• Dynamic Value + json — json.parse is a transcription of the NORMATIVE self-hosted parser (stdlib/json_parse.almd, ALS-T3): deliberately lenient (EOF closes strings, invalid \uXXXX/unknown escapes drop silently, surrogate pairs join, :/separators optional where the oracle is, trailing input ignored, char-index error positions); stringify uses the canonical 5-escape rule; value.*/json.* accessors, paths, pretty.
• bytes — reference semantics pinned by fixtures: let/var bindings SNAPSHOT the buffer (mutable_global_repeat_writes), call arguments ALIAS it (bytes_param_writeback); reads are TOTAL per value (any not-fully-in-range window reads 0 — bytes_negative_offset_family, bytes_f16_offset_overflow); OOB set_* are silent no-ops; copy_from/copy_within clamp; C-197 out of memory and C-034 repeat result too large aborts; f16→f64 exact (ALS-D5); cursor writers incl. write_string_be.
• Vendored musl libm (ref/src/libm.rs) — the same upstream the runtime vendors; bit-agreement confirmed over math_transcendental_bits / trig_libm / math_atan_tanh / math_log_gamma (Lanczos with exact bit constants).
• Int doctrine — + - * ** wrap two's-complement (int_pow_overflow_wraps, toplevel_const_wrapping, choose-at-i64::MAX); / % keep the T6 aborts. Float ops canonicalize NaN to 0x7FF8… (nan_canonical_observation); Float %/** via vendored fmod semantics/pow.
• fs/env/io/process effects with io::Error text passthrough (fs_read_directory_errno, fs_read_text_utf8); *_if_exists → ok(none); walk/list_dir byte-lex without host sort.
• civil calendar (translated from stdlib/datetime_calendar.almd, wrapping/truncating exactly), SHA-256 + FNV-1a, base64 with the pinned error strings, hex/path/args/random (fixed-seed splitmix64 — the ALS asserts only range), http offline builders (case-insensitive last-wins headers), list OOB write doctrine (insert as-usize-clamps, set/update/swap/remove_at no-op), C-199 fan first-err order, fan mapper forms, pad first-char-or-space rule.

New findings for PARSER-NOTES

Recorded in the Measured block; the doctrine sentences above each cite their pinning fixture.