Update docs, configs, and scripts

Co-Authored-By: Oz <oz-agent@warp.dev>

backend/config/model.env.example

@@ -1,6 +1,8 @@
+# Generated from .env by scripts/install.sh and scripts/restart.sh
+# Keep values in .env as the source of truth.
 HF_TOKEN=YOUR_HF_TOKEN_HERE
 VLLM_API_KEY=YOUR_LOCAL_API_KEY_HERE
-GEMMA_MODEL_ID=google/gemma-3-1b-it
+GEMMA_MODEL_ID=SET_IN_DOT_ENV
 BACKEND_PORT=8000
 HUGGINGFACE_CACHE_DIR=/home/${USER}/.cache/huggingface
 VLLM_MAX_MODEL_LEN=4096