feat(ai): introduce dedicated AI roles and wiring; clean up legacy AI stack

• Add svc-ai category under roles and load it in constructor stage

• Create new 'svc-ai-ollama' role (vars, tasks, compose, meta, README) and dedicated network

• Refactor former AI stack into separate app roles: web-app-flowise and web-app-openwebui

• Add web-app-minio role; adjust config (no central DB), meta (fa-database, run_after), compose networks include, volume key

• Provide user-focused READMEs for Flowise, OpenWebUI, MinIO, Ollama

• Networks: add subnets for web-app-openwebui, web-app-flowise, web-app-minio; rename web-app-ai → svc-ai-ollama

• Ports: rename ai_* keys to web-app-openwebui / web-app-flowise; keep minio_api/minio_console

• Add group_vars/all/17_ai.yml (OLLAMA_BASE_LOCAL_URL, OLLAMA_LOCAL_ENABLED)

• Replace hardcoded include paths with path_join in multiple roles (svc-db-postgres, sys-service, sys-stk-front-proxy, sys-stk-full-stateful, sys-svc-webserver, web-svc-cdn, web-app-keycloak)

• Remove obsolete web-app-ai templates/vars/env; split Flowise into its own role

• Minor config cleanups (CSP flags to {}, central_database=false)

https://chatgpt.com/share/68d15cb8-cf18-800f-b853-78962f751f81

roles/web-app-openwebui/README.md

@@ -0,0 +1,24 @@
+Here are user-focused **README.md** drafts for the four roles, following your template structure and describing the **role** (what the installed software does for users), not the folder.
+
+# Open WebUI
+
+## Description
+
+**Open WebUI** provides a clean, fast chat interface for working with local AI models (e.g., via Ollama). It delivers a ChatGPT-like experience on your own infrastructure to keep prompts and data private.
+
+## Overview
+
+End users access a web page, pick a model, and start chatting. Conversations remain on your servers. Admins can enable strict offline behavior so no external network calls occur. The UI can also point at OpenAI-compatible endpoints if needed.
+
+## Features
+
+* Familiar multi-chat interface with quick model switching
+* Supports local backends (Ollama) and OpenAI-compatible APIs
+* Optional **offline mode** for air-gapped environments
+* File/paste input for summaries and extraction (model dependent)
+* Suitable for teams: predictable, private, reproducible
+
+## Further Resources
+
+* Open WebUI — [https://openwebui.com](https://openwebui.com)
+* Ollama — [https://ollama.com](https://ollama.com)