refactor: split glm.c into colibri.c + 4 header modules

Rename glm.c → colibri.c and extract four self-contained modules
into header-only files (same pattern as st.h/tier.h/grammar.h):

  quant.h      (672 lines) — SIMD matmul kernels, quantization
  sample.h     (143 lines) — RNG, top-p sampling, stop-set
  kv_persist.h (121 lines) — .coli_kv disk persistence
  telemetry.h  (189 lines) — dashboard protocol, stats, usage

Main engine file shrinks from 6588 to 5396 lines (−18%).

Build system: primary target is now colibri$(EXE); `make glm`
remains as a phony alias for backward compat. CI, setup.sh,
coli CLI, and all 10 test files that include the engine are
updated. make check passes (C + Python, 73 tests, zero warnings).

c/setup.sh

@@ -32,11 +32,11 @@ esac
 
 # 2) build: nativa (veloce, per QUESTA macchina). Per un binario da distribuire: make portable
 echo "  building (ARCH=${ARCH:-native})…"
-make -s glm ARCH="${ARCH:-native}"
+make -s colibri ARCH="${ARCH:-native}"
 
 # 3) self-test sull'oracolo tiny, se presente
 if [ -d glm_tiny ] && [ -f ref_glm.json ]; then
-    r=$(SNAP=./glm_tiny TF=1 ./glm 64 16 16 2>/dev/null | grep -oE "[0-9]+/[0-9]+ positions" || true)
+    r=$(SNAP=./glm_tiny TF=1 ./colibri 64 16 16 2>/dev/null | grep -oE "[0-9]+/[0-9]+ positions" || true)
     echo "  engine self-test: ${r:-?}  (expected 32/32)"
 fi