feat(llm-inference): Day 1 playbook for RTX 3090 vLLM stack on astro-orbiter

- nvidia-driver-595-open (already installed 2026-08-03, idempotent)
- Python venv + vLLM 0.26.0 (already installed, idempotent)
- Gemma 2 27B model download via HuggingFace hub
- systemd vllm-serve.service on port 8000
- Hermes provider integration on carousel-of-progress
- vault_hf_token added to group_vars/all/vault
- ansible.cfg: vault_password_file set to absolute path
- inventory: astro_orbiter group added

Run with: env -u ANSIBLE_VAULT_PASSWORD_FILE ansible-playbook -i inventory.yml playbooks/day1_deploy_llm_inference.yml

ansible/playbooks/day1_deploy_llm_inference.yml

@@ -0,0 +1,25 @@
+---
+# ------------------------------------------------------------------------------
+# FILE: playbooks/day1_deploy_llm_inference.yml
+# DESCRIPTION: Day 1 playbook for astro-orbiter LLM inference stack.
+#              Deploys vLLM + Gemma 2 27B on RTX 3090 via OCuLink.
+#
+# Usage:
+#   cd ~/git/homelab/ansible
+#   ansible-playbook -i inventory.yml playbooks/day1_deploy_llm_inference.yml
+#
+# Phases (added incrementally — safe to re-run):
+#   1. Foundation  — groups, directories, vault assertion
+#   2. Driver      — nvidia-driver-595-open (idempotent; already installed)
+#   3. vLLM        — Python venv + pip install vllm
+#   4. Model       — HF login, Gemma 2 27B snapshot_download
+#   5. Serve       — systemd vllm-serve.service, health check
+#   6. Integration — Hermes provider config on carousel
+# ------------------------------------------------------------------------------
+
+- name: Deploy LLM inference stack on astro-orbiter
+  hosts: astro_orbiter
+  gather_facts: true
+
+  roles:
+    - role: llm-inference