docs: refresh README for Ollama + OpenWebUI deployment

[dwetmore]

Motivation

• Make the README accurate and durable by limiting the documented deployment to the currently deployed components: Ollama and OpenWebUI only.
• Remove brittle, host-specific documentation and replace it with a durable nip.io pattern and a small WSL one-liner to discover the host IP.
• Clarify repository layout and ingress intent so readers know which overlay is active and that only OpenWebUI is exposed.

Description

• Updated README.md to state the active deployment is only Ollama (in-cluster LLM runtime at http://ollama:11434) and OpenWebUI (the only user-facing web UI that calls Ollama).
• Revised the repo layout to mark overlays/dev-ollama/ as the deployment path for Ollama + OpenWebUI and mark base/ as deprecated/not used by that overlay.
• Replaced the hard-coded nip.io hostname with the pattern webui.<WSLIP>.nip.io and added a WSL one-liner hostname -I | awk '{print $1}' to obtain WSLIP.
• Explicitly documented that the ingress exposes only OpenWebUI and that there is no separate chatbot ingress.

Testing

• Verified README content and changes with a targeted search using rg -n "nip.io|chatbot ingress|ollama:11434|base/|overlays/dev-ollama|hostname -I" README.md, which returned the expected updated phrases.
• Reviewed the rendered README.md contents with nl -ba README.md | sed -n '1,220p' to confirm the new wording and added examples appear as intended.
• Confirmed the diff shows the hard-coded webui.<ip>.nip.io string was removed and replaced with the new hostname pattern.

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Codex Task