Update LLM support for llama.cpp and enhance configuration management

- Added support for `llamacpp-models.yaml` in `.gitignore` and implemented logic to copy it in `gpu-rent.ps1` and `gpu-rent.sh`.
- Enhanced CLI to prompt for llama.cpp model presets during setup and execution, improving user experience.
- Updated configuration handling to include `llamacpp_models_manifest` and related functions for managing llama.cpp models.
- Improved documentation in `cli.md` and `llm.md` to reflect changes in llama.cpp integration and model management.
- Refactored provisioning logic to handle llama.cpp model downloads and configurations effectively.

tests/test_llamacpp_models.py

@@ -0,0 +1,31 @@
+from pathlib import Path
+
+from gpu_rent.llm_runtime import (
+    gguf_filename_from_url,
+    parse_llamacpp_models,
+    write_llamacpp_models_preset,
+)
+
+
+def test_gguf_filename_from_url():
+    url = (
+        "https://huggingface.co/org/repo/resolve/main/"
+        "Qwen2.5-3B-Instruct-Q4_K_M.gguf"
+    )
+    assert gguf_filename_from_url(url) == "Qwen2.5-3B-Instruct-Q4_K_M.gguf"
+
+
+def test_write_and_parse_llamacpp_preset(tmp_path: Path):
+    path = tmp_path / "llamacpp-models.yaml"
+    write_llamacpp_models_preset(path, "light")
+    entries = parse_llamacpp_models(path)
+    assert len(entries) == 1
+    assert entries[0].default is True
+    assert "Qwen2.5-3B" in entries[0].url
+    assert entries[0].url.startswith("https://")
+
+
+def test_parse_llamacpp_empty(tmp_path: Path):
+    path = tmp_path / "llamacpp-models.yaml"
+    write_llamacpp_models_preset(path, "empty")
+    assert parse_llamacpp_models(path) == []