#952 BrokePipeError when terminating Strata on Linux

Descripción

After Ctrl+c to terminate the engine i get:
```
[strata] stopping (Ctrl+C again to end the engine at once) ...
Traceback (most recent call last):
  File "/home/mike/Programs/Strata/serve/server.py", line 4129, in main
    time.sleep(1)                               # Windows never delivers Ctrl+C to an untimed Event.wait()
    ^^^^^^^^^^^^^
KeyboardInterrupt

During handling of the above exception, another exception occurred:

BrokenPipeError: [Errno 32] Broken pipe

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/home/mike/Programs/Strata/serve/server.py", line 4145, in <module>
    sys.exit(main())
             ^^^^^^
  File "/home/mike/Programs/Strata/serve/server.py", line 4136, in main
    close()
  File "/home/mike/Programs/Strata/serve/server.py", line 1253, in close
    self.proc.stdin.close()
```
The engine itself runs great! Here is my setup:

Strata v0.1.39
Ubuntu 24.04.5 LTS
Intel® Core™ Ultra 5 245K
64Gb RAM
2x RTX 5060ti 16Gb (used --gpus 0,1), RTX 3060 12Gb (not used)

model.json:
```
{
 "exe": "/home/mike/Programs/Strata/engine/strata",
 "args": [
  "--pack",
  "/home/mike/Programs/Strata-data/packs/swift-iq3_xxs",
  "--native",
  "/home/mike/Programs/Strata-data/models/swift-IQ3_XXS/Swift-Qwen3.8-Flash-Next-GSQ-RCO-IQ3_XXS-00001-of-00002.gguf",
  "--ple-gguf",
  "/home/mike/Programs/Strata-data/models/swift-IQ3_XXS/Swift-Qwen3.8-Flash-Next-GSQ-RCO-IQ3_XXS-00001-of-00002.gguf",
  "--expert-profile",
  "/home/mike/Programs/Strata/data/expert-profile.bin",
  "--expert-cache",
  "auto",
  "--prefill",
  "auto",
  "--spec",
  "4",
  "--mtp",
  "/home/mike/Programs/Strata-data/mtp/rt",
  "--max-context",
  "184320",
  "--kv",
  "q4_0",
  "--kv-resident",
  "32768",
  "--pcie-frac",
  "0.00",
  "--spec-min-p",
  "0.70",
  "--slots",
  "2"
 ],
 "cwd": "/home/mike/Programs/Strata",
 "tokenizer": "/home/mike/Programs/Strata-data/packs/swift-iq3_xxs/tokenizer",
 "model_name": "swift-1.5-iq3_xxs",
 "effort_position": "end",
 "log": "/home/mike/Programs/Strata/strata-swift-iq3_xxs.log",
 "lib_dirs": [
  "/usr/local/cuda-13.3/bin",
  "/usr/local/cuda-13.3/lib64"
 ],
 "port": 1234,
 "gpu": [
  0,
  1
 ],
 "gpus_asked": true,
 "layer_split": "auto"
}
```