fix(oracle): create glm_tiny/ before saving so a fresh checkout works

make_glm_oracle.py wrote glm_tiny/model.safetensors and glm_tiny/config.json
without creating the directory first. safetensors.save_file writes a temp file
inside the target dir before the atomic rename, so on a clean checkout (no
pre-existing glm_tiny/) it aborts with an opaque error:

    SafetensorError: Error while serializing: I/O error:
    The system cannot find the path specified. (os error 3)
    at path ".../glm_tiny/.tmpXXXXXX"

The directory only ever existed because it was left over from a previous run,
so the first-ever `python tools/make_glm_oracle.py` fails for every new user
following the README's verify step.

Create glm_tiny/ with Path.mkdir(parents=True, exist_ok=True) before the save
branch — covers the fp8 path, the bf16 path, and config.json. Path is already
imported; no new dependency, no change to the CPU build.

c/tools/make_glm_oracle.py

@@ -115,6 +115,7 @@ print("tf_pred:", tf_pred)
 sd = model.state_dict()
 unfuse_experts(sd)
 
+Path("glm_tiny").mkdir(parents=True, exist_ok=True)   # safetensors/json won't create the dir themselves
 if args.fp8:
     n_fp8, n_tot = save_fp8_safetensors(sd, "glm_tiny/model.safetensors")
     print(f"\nsaved FP8: {n_fp8} e4m3 tensors (+{n_tot - n_fp8} scale_inv sidecars / f32) "