Ember v0.6.2

Changed

• Q4_K/Q6_K production matmul now uses canonical transient Q8_K activation
  packing and integer dots for decode and prefill. The exact-f32 dequantize/dot
  implementation remains an explicit slow oracle. Non-finite activations fail
  before destination mutation; warmed workspace and accumulate semantics are
  explicit contracts.
• Execution plans retain loader fallback provenance and identify the numerical
  runtime with kernel_revision = 2 while preserving offline verification and
  hashes of historical revision-1 plans. Plan/dispatch disagreement is a
  release-mode error, and the cache key now includes Rayon thread count.
• The superseded internal K-quant modules (k_gemv, k_prefill,
  k_matmul_x86) and their ad-hoc examples/benches were replaced by
  k_quant_matmul. Ember's Rust library is internal/unstable; this is an
  intentional source-level break rather than compatibility shims over dead hot
  paths.
• The v0.4 planned-decode interpreter moved out of src/llama.rs into
  src/planned_decode.rs (resolved ops, scratch-arena session, planned and
  fused kernels, forward_last_logits_planned). Zero behavioral change;
  src/llama.rs keeps the model, eager forward, dispatch, and plan
  construction. The v0.5 research contract's reference to the interpreter
  path was updated accordingly.
• Toolchain pinned via rust-toolchain.toml to 1.92.0 (the declared MSRV
  and CI toolchain); local builds now match CI.
• Dependencies: crossbeam-epoch 0.9.18 → 0.9.20 (RUSTSEC-2026-0204),
  anyhow → 1.0.104 (RUSTSEC-2026-0190), memmap2 → 0.9.11
  (RUSTSEC-2026-0186). cargo audit is now part of CI.

Added

• First-class KV-prefix snapshots for the Llama/Qwen CPU runtime through the
  ember kv command family: deterministic ember.kv-snapshot.v1 artifacts,
  strict integrity and compatibility checks, bit-exact same-model replay,
  cache comparison and perturbation diagnostics, replay traces, and explicit
  RoPE remove/reapply research utilities. The validation matrix and benchmark
  evidence are recorded under artifacts/benchmark-kv-v1/2026-08-08/.
• The bilingual “Road to Ember 1.0” documentation series and a substantial
  native-console visual refresh, while preserving the same v0.5 experiment
  execution path and offline behavior.
• A pinned llama.cpp known-answer verifier for Q8_K bytes and Q4_K/Q6_K dots,
  fail-closed 1B real-model scalar/x86 validation, a dedicated x86 CI gate,
  adversarial kernel matrices, and schema-4 path-interleaved benchmark output
  with checksums and full dispatch/workspace provenance.
• tests/property.rs: proptest suite (tensor shape ops vs hand-rolled
  references, decode-arena disjointness/alignment/isolation, K-quant dequant
  contracts) plus fuzz-style robustness tests for the untrusted-input
  boundaries: the GGUF loader, the v0.5 spec parser, and the npy reader must
  never panic on arbitrary input.
• benches/hooks_overhead.rs: planned-decode cost with a noop experiment
  runner attached vs bare (Gate H evidence; measured ≈0% overhead).
• Rustdoc lints (broken_intra_doc_links, private_intra_doc_links) and a
  CI docs step (RUSTDOCFLAGS=-D warnings cargo doc).

Fixed

• forward_last_logits_planned had hard-coded ExecutionMode::Planned, so
  planned-fused parity tests never executed F1-F5. It now routes the model's
  actual mode; tests use execution counters. This exposed Q8_0 F5 overwriting
  the residual (Q8_0 assigns rather than accumulates), so Q8_0 F5 now de-fuses
  with a serialized reason while f32 and canonical K kernels execute F5.
• Owned reader-backed K weights now receive the loader-resolved execution tier
  at construction, matching mmap-backed weights. Loader fallback reasons and
  original dtype survive model construction into execution plans.
• Build provenance now exports the EMBER_GIT_COMMIT name consumed by plans,
  traces, and benchmarks (plus dirty-tree status for benchmark records).
• tests/k_parity.rs::v04_planned_inactive_hooks_real_model failed on Q8_0
  models: the plain run uses the v0.3 native fast path (contract D1) while
  the hooked run uses the generic hooked path, so bit-exact logits were not
  the right contract there (tokens always matched). The test now skips
  models without K-quant tensors; all parity suites (Q8_0, Q6_K, Q4_K_M)
  pass 5/5.
• All 8 rustdoc warnings (math-notation brackets parsed as links,
  private-item links, unclosed HTML tag in a doc comment).
• Stale #[allow(dead_code)] on KQuantWeight::try_from_mmap (the loader
  calls it), on the generic LlamaMlp/Attention/Block structs, and dead
  gemma4 forward_full paths (test-only attention ported behind
  #[cfg(test)]).
• // Safety: comments on the previously undocumented unsafe sites: the
  matrixmultiply::sgemm call in tensor.rs and 29 SIMD kernels in
  simd.rs.