colibri v1.7.0

71 pull requests since v1.6.2. A sixth model family with its GPU tier, a
rebuilt expert-matmul path, and the CI that would have caught the class of bug
we shipped twice.

A sixth engine: Qwen3.6-35B-A3B — CPU and GPU

• #712 (@kreuzzelg) — hybrid Gated Attention + Gated DeltaNet + streaming
  MoE, in c/qwen36.c. Pre-converted containers published (int4-gs64
  recommended: cosine to the int8 anchor 0.98777 → 0.99313, KL 0.109 → 0.080
  vs per-row). The engine takes any architecture-identical checkpoint
  unchanged — KAT-Coder v2.5 runs on it with no code path of its own.
• #713 (@kreuzzelg) — CUDA VRAM expert tier with heat-based placement
  across GPUs: 1.44 → 10.05 tok/s (7.0×) on 2× 8 GB cards, output
  bit-identical to CPU (cmp over the full 200-token generation), measured
  cold with no heat table. A qt_ready() gate keeps CPU-only builds from
  allocating the packed int4 buffers they never read: 7.33 GB saved.

The expert matmul path, rebuilt (all bit-identical)

• #1071 / #1075 / #1076 / #1077 — activation quantization hoisted to layer
  level across GLM, Kimi K3 and DeepSeek V4: the same vector was being
  re-quantized ~16× per layer, serially. Removes ~5.2 ms/token of serial time
  and every per-call malloc from the hot path.
• #1079 / #1086 — K1: plane-nibble int4 layout + unsigned-VNNI dot.
  Storing element k and k+32 in one byte deletes the unpack, and since
  nibbles are stored unsigned, dot(v,x) = dot(u,x) − 8·Σx feeds vpdpbusd
  natively. 8 uops per 64 MACs instead of 32: 1.45–2.65× on the IDOT
  kernels, zero bytes added.
• #1088 — K2: 1×4 union tile. The prefill union hands each expert
  2–16 rows; the weight block's load+mask is now paid once per four rows
  instead of once per row: 2.67–3.10× at S=4 (peak 253 GMAC/s).
• #1093 — parallel silu and the down-side activation hoist.
• #1094 — K1b: grouped planar IDOT for gs64 containers (IDOT_GS=1,
  opt-in): the recommended container format could not reach the integer
  kernels at any batch size before this.
• #1082 (@outtodata) — FUSED3=1 opt-in fused AVX2 expert matmul.

Streaming and I/O

• #1097 — DeepSeek V4 expert-loader pool default 3 → 9 lanes:
  1.41× decode on the real V4-Flash checkpoint (8 interleaved runs on a
  quiet 25 GB box). V4_LOADER_LANES still overrides.
• #1056 (@dcutugno) — DeepGEMM sm120 headers fetched at a pinned commit on
  first build: 2.5× prefill on sm120 with nothing vendored in-tree.
• #988 / #1054 / #1055 — DeepSeek V4 CUDA tier and dual-SSD mirror.

Correctness and CI

• #1083 — ARM CI job (ubuntu-24.04-arm) plus an integer-kernel
  bit-exactness gate that runs on both ISAs. Every tiny-oracle job ran on x86
  before this, so NEON-divergent paths were invisible — which is how the IDOT
  defaults below shipped. Closes #1081.
• #1044 / #1080 — IDOT made opt-in in olmoe and inkling: the fast path is
  x86-only and quantizes activations, so the same model produced different
  tokens on x86 and ARM by default.
• #1109 (@SebaWag) — ARM64 dotprod probed by compiling the intrinsic:
  GCC 11 defines __ARM_FEATURE_DOTPROD for a base it cannot emit
  vdotq_s32 for. Fixes #1104.
• #1111 — __syncwarp() after grouped_s4_wmma's store (reported by
  @monotophic with compute-sanitizer evidence). Fixes #1099.
• #1073 / #1074 (@bherald) — Kimi K3 cancels prefill between layers
  instead of holding the engine for a minutes-long prompt; cancelled requests
  no longer count as completed.

Apple Silicon

• #790 → #1113 (@RDouglasSharp) — Metal backend for Kimi K3: KDA state and
  window buffers aligned, wrap-once buffer cache, CPU-side MLA KV cache. 1.7×/2.4×
  on the compute-bound phases (KDA attention + projections dispatched to the GPU);
  MoE experts stay on the CPU. Kimi K3's first GPU backend.

More correctness fixes

• #1098 (@monotophic) — __syncthreads() missing from the absorb softmax
  reduction, with a determinism test that reproduces the hazard.
• #1101 (@monotophic) — allocation and snprintf results checked on the
  checkpoint-load path (#798).
• #1100 / #1108 (@monotophic) — fmt=8/fmt=6 scale-byte accounting in
  tensor_bytes/tensor_free, and weights_owned set before the host-to-device
  copy so a failed upload frees its buffer. Each ships with its own regression
  test; all four of this contributor's CUDA fixes landed in this release.
• #1122 (@ZacharyZcR) — USAGE_SAVE=0 honoured in every engine (#1039): the
  history was loaded but written back anyway, which quietly contaminated any A/B
  that shared a usage file between arms.
• #1121 (@ZacharyZcR) — LRU victim selection now respects a lowered ecap
  (#1034): after an RSS-guard reduction the cache kept evicting against the old
  capacity.
• #1123 (@ZacharyZcR) — the v1.6.2 warning-cleanup patches landed (#1032).
• #1106 (@monotophic) — duplicate tensor names across indexed shards are now
  refused rather than silently resolved to one of them (untrusted containers).

Interfaces

• #829 (@aaristov) — GPU-vs-fallback counters and chat status made visible in
  coli serve: the tier's behaviour is now observable instead of inferred.
• #1095 (@benmaster82) — OLMoE planner geometry adapter, and #1103
  (@SebaWag) — Kimi K3, Inkling and DeepSeek V4 adapters with 23 tests: every
  family now has real planner geometry, so coli plan stops guessing (#1066).
• #1096 (@terrizoaguimor) — DeepSeek V4 serve framing on the shared codec,
  completing the codec migration across OLMoE, Kimi K3 and V4.
• #1063 / #1068 (@terrizoaguimor) — model families are registry-owned:
  coli, the gateway, doctor and the planner read one descriptor table.
• #1087 / #1090 / #1096 / #1116 (@terrizoaguimor) — a shared serve framing
  codec, now adopted by every engine: OLMoE, Kimi K3, DeepSeek V4 and
  Inkling (whose audio payload rides as an opaque extension). Each migration
  landed behind a byte-exact wire-transcript freeze, so the gateway contract is
  provably unchanged. Byte framing had been duplicated five times, which is how
  Windows binary mode silently disappeared from sibling engines (#748).
• #1036 (@lineape) — distributed expert workers (LAN, opt-in via
  CLUSTER_WORKERS).
• Planner: DeepSeek V4 expert naming now recognized, so coli plan and
  coli doctor stop counting every routed expert as dense (fixes #1110).