ucode pi automatic model detection

[MarkAngler]

1. launching ucode pi automatically detects available models
2. the automatically detected models are not comprehensive
   "models": [
   {
   "id": "system.ai.claude-haiku-4-5"
   },
   {
   "id": "system.ai.claude-opus-4-8"
   },
   {
   "id": "system.ai.claude-sonnet-5"
   }
   ]
   "models": [
   {
   "id": "system.ai.gpt-oss-120b"
   },
   {
   "id": "system.ai.gpt-oss-20b"
   }
   ]
3. if you try to modify the providers manually, ucode just overwrites them on next launch.