Add ansible playbook for indri with prometheus and grafana roles

- Inventory with tailnet hosts (indri, gilbert, sifaka)
- Prometheus role: installs via homebrew, templates config from current indri setup
- Grafana role: installs via homebrew, starts service
- ansible.cfg and requirements.yml for community.general collection
- Updated CLAUDE.md with ansible dry-run instructions

Tested: ansible-playbook playbooks/indri.yml --check --diff (all ok)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

ansible/inventory/hosts.yml

@@ -0,0 +1,14 @@
+all:
+  children:
+    servers:
+      hosts:
+        indri:
+          ansible_host: indri
+    workstations:
+      hosts:
+        gilbert:
+          ansible_host: gilbert
+    nas:
+      hosts:
+        sifaka:
+          ansible_host: sifaka