Replace ReSpec + Python generator with a generic EKGF ontology publisher

[jgeluk]

Goal (parked — plan for later)

Retire the current DPROD-specific spec generator (`spec-generator/` Python + `respec/template.html`) in favour of a generic EKGF ontology publisher that can render any EKGF ontology — not just DPROD — into a consistent, modern, non-ReSpec website.

Motivation

• The current generator is hand-rolled for DPROD and reuses W3C ReSpec conventions, which date the output and make it hard to evolve the design.
• Other EKGF ontologies face the same publishing problem. A single reusable tool would let each ontology repo drop in config and get a polished site for free.
• Consolidating on the `ekgf-website` stack (Next.js / Tailwind / shadcn) would let ontology pages share components, navigation, and design tokens with https://ekgf.org and the new DPROD marketing site (Marketing / explainer website for DPROD #174).

Scope sketch

• Input: OWL + SHACL files, examples directory, ontology metadata.
• Output: rendered Next.js pages (or MDX) with class/property tables, examples, diagrams.
• Lives in its own repo or as a package, consumed by dprod and other ontology repos.

Depends on / relates to

• Marketing / explainer website for DPROD #174 — the marketing site establishes the design system this generator would target.
• Per-branch Vercel preview deployments for DPROD #175 — per-branch previews make rolling out a new generator low-risk.

Priority

Parked. Do not start until #174 lands and we've learned from it. Opening this issue now to capture the direction so it doesn't get lost.