Unify continuous batching + heterogeneous runtime: decode batching, physical-core planning, disjoint VRAM/RAM placement, topp-policy warning (CPU-validated, CUDA on 6x5090) (#68)

* Fuse CUDA expert MLP execution

* Group CUDA expert transfers by device

* Instrument grouped CUDA expert execution

* Bound grouped CUDA decode scratch

* Execute expert groups across GPUs in parallel

* Release host backing for multi-GPU experts

* Define quality-preserving memory policies

* Overlap cold expert loading with resident compute

* Adapt expert placement with session LFRU

* Fuse q4 expert gate and up dispatch

* Plan CPU work on physical cores

* Batch grouped expert CUDA kernels

* Separate VRAM and RAM expert placement

* Add ragged multi-sequence decode forward

* feat(runtime): add continuous decode scheduler

* Route concurrent API requests through batch scheduler

* Harden multiplex request lifecycle and framing

* Cancel disconnected multiplex requests

* Bind API port before starting the engine

* fix automatic KV slot allocation

* add native int4 Tensor Core grouped GEMM

* add Tensor Core throughput benchmark

* optimize packed int4 low-row kernels

* add asynchronous CUDA staging streams

* document validated six-GPU dense acceleration

* tune six-GPU expert hot set

* raise validated expert hot-set target

* add CUDA MLA absorption core

* fuse grouped expert gate and up projections

* Warn for explicit lossy routing flags

c/tests/test_decode_batch.c

@@ -0,0 +1,56 @@
+#include <assert.h>
+#include <stdio.h>
+
+#include "../decode_batch.h"
+
+static void test_rows_use_their_own_sequence_storage(void)
+{
+    float sequence_a[4 * 3] = {0};
+    float sequence_b[4 * 3] = {0};
+
+    float *a2 = coli_kv_row(sequence_a, 2, 3);
+    float *b1 = coli_kv_row(sequence_b, 1, 3);
+    a2[0] = 20.0f;
+    b1[2] = 12.0f;
+
+    assert(a2 == &sequence_a[6]);
+    assert(b1 == &sequence_b[3]);
+    assert(sequence_a[6] == 20.0f);
+    assert(sequence_b[5] == 12.0f);
+    assert(sequence_a[5] == 0.0f);
+    assert(sequence_b[6] == 0.0f);
+}
+
+static void test_const_reader_selects_the_same_row(void)
+{
+    float storage[5 * 7] = {0};
+    const float *row = coli_kv_row(storage, 4, 7);
+
+    assert(row == &storage[28]);
+}
+
+static void test_submit_header(void)
+{
+    ColiSubmit sub;
+    assert(coli_submit_parse("SUBMIT 42 3 17 64 0.7 0.95", &sub));
+    assert(sub.id == 42 && sub.slot == 3 && sub.bytes == 17);
+    assert(sub.max_tokens == 64 && sub.temperature > .69f && sub.top_p > .94f);
+    assert(!coli_submit_parse("SUBMIT 1 -1 2 3 0.7 1", &sub));
+    assert(!coli_submit_parse("SUBMIT 1 0 2 0 0.7 1", &sub));
+    assert(!coli_submit_parse("SUBMIT 1 0 2 3 4 1", &sub));
+    assert(!coli_submit_parse("SUBMIT 0 0 2 3 1 1", &sub));
+    assert(!coli_submit_parse("SUBMIT 1 0 2 3 nan 1", &sub));
+    assert(!coli_submit_parse("SUBMIT 1 0 2 3 1 inf", &sub));
+    assert(coli_submit_parse("SUBMIT 1 0 16777216 3 1 1", &sub));
+    assert(!coli_submit_parse("SUBMIT 1 0 16777217 3 1 1", &sub));
+    assert(!coli_submit_parse("SUBMIT 1 0 2 3 1 1 trailing", &sub));
+}
+
+int main(void)
+{
+    test_rows_use_their_own_sequence_storage();
+    test_const_reader_selects_the_same_row();
+    test_submit_header();
+    puts("decode batch helper tests: ok");
+    return 0;
+}