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).

.gitignore

@@ -10,6 +10,8 @@ desktop/src-tauri/target/
 desktop/src-tauri/gen/
 
 # binari compilati (si rigenerano con make / coli build)
+c/colibri
+c/colibri.exe
 c/glm
 c/glm.exe
 c/olmoe