docs: rewrite README with structured overview and quick start guide

Replaces the minimal project description with a comprehensive README
including a component overview table, quick start instructions, common
Ansible operations, and links to detailed documentation. Aligns with
Red Panda Approval™ standards.

ansible/inventory/host_vars/portia.incus.yml

@@ -0,0 +1,48 @@
+---
+# Portia Configuration - Relational Database Host
+# Services: alloy, postgresql
+# Note: PgAdmin moved to Prospero (PPLG stack)
+
+services:
+  - alloy
+  - postgresql
+
+# Alloy
+alloy_log_level: "warn"
+
+# PostgreSQL Config
+postgres_user: postgres
+postgres_group: postgres
+postgresql_port: 5432
+postgresql_data_dir: /var/lib/postgresql
+arke_db_name: arke
+arke_db_user: arke
+arke_db_password: "{{ vault_arke_db_password }}"
+anythingllm_db_name: anythingllm
+anythingllm_db_user: anythingllm
+anythingllm_db_password: "{{ vault_anythingllm_db_password }}"
+# Note: Casdoor uses dedicated PostgreSQL on Titania (not Portia)
+gitea_db_name: gitea
+gitea_db_user: gitea
+gitea_db_password: "{{ vault_gitea_db_password }}"
+lobechat_db_name: lobechat
+lobechat_db_user: lobechat
+lobechat_db_password: "{{ vault_lobechat_db_password }}"
+nextcloud_db_name: nextcloud
+nextcloud_db_user: nextcloud
+nextcloud_db_password: "{{ vault_nextcloud_db_password }}"
+openwebui_db_name: openwebui
+openwebui_db_user: openwebui
+openwebui_db_password: "{{ vault_openwebui_db_password }}"
+spelunker_db_name: spelunker
+spelunker_db_user: spelunker
+spelunker_db_password: "{{ vault_spelunker_db_password }}"
+hass_db_name: hass
+hass_db_user: hass
+hass_db_password: "{{ vault_hass_db_password }}"
+nike_db_name: nike
+nike_db_user: nike
+nike_db_password: "{{ vault_nike_db_password }}"
+
+# PostgreSQL admin password
+postgres_password: "{{ vault_postgres_password }}"