Enhance LLM configuration and installation scripts for improved flexibility

- Added new environment variables in `env.example` and `gpu-rent.vars.example` for fine-tuning LLM settings, including CUDA build options and model version pinning.
- Updated `llm.md` documentation to include detailed descriptions of new configuration options and usage cases for LLM setups.
- Enhanced the `provision.py` script to forward new environment variables during remote installations, improving the installation process for LLM components.
- Modified the `install_llamacpp.sh` script to support conditional CUDA builds and asset URL overrides, ensuring better compatibility with various environments.
- Improved logging in the installation scripts to provide clearer feedback during the setup process.

env.example

@@ -46,6 +46,17 @@ OLLAMA_LOCAL_PORT=17811
 LLAMACPP_LOCAL_PORT=17812
 # OLLAMA_MODELS_MANIFEST=
 # LLAMACPP_MODELS_MANIFEST=
+# Pin / тонкая настройка LLM (несecреты; удобнее в gpu-rent.vars — см. кейсы A–H):
+# LLAMACPP_TAG=b10545
+# LLAMACPP_BUILD_CUDA=1
+# LLAMACPP_FORCE_REINSTALL=1
+# LLAMACPP_ASSET_URL=
+# LLAMACPP_SHA256=
+# LLAMACPP_NGL=40
+# LLAMACPP_CTX=4096
+# LLAMACPP_EXTRA_ARGS=--flash-attn on
+# OLLAMA_VERSION=0.6.5
+# OLLAMA_SHA256=
 # CIVITAI_API_TOKEN=
 # CIVITAI_API_HOST=civitai.red
 # Hugging Face (GGUF / gated HF URLs / capture fallback metadata):