feat: rename to paperspec and add the website

- Rename manuspec to paperspec everywhere outside pixi.toml: prose, the
  tools, provenance tool names and the fixture key derivations, so every
  fixture and vector is rebuilt.
- Move the namespace addresses under the site, mirroring the repository:
  schema $id https://paperspec.scient.ing/schemas/<file>, the JSON-LD
  context https://paperspec.scient.ing/context/scienting-1.jsonld, and
  term IRIs https://paperspec.scient.ing/vocab#<term>. Format
  identifiers (scienting-*) and URNs (urn:scienting:) are unchanged.
- tools/site.py (standard library only) builds _site/: every file of the
  repository at its own path, each Markdown file rendered as a page with
  sidebar navigation, heading anchors matching the forge's, folder
  listings, a vocabulary page for the context's IRIs, a heading search
  and a 404 page; light and dark themes.
- check.py builds the site and checks that every Markdown file has a
  page, every internal link and fragment resolves, no Markdown is left
  unrendered, and every $id, the context address and the vocabulary IRIs
  are files of the site.
- deploy/: a Caddyfile with the media types and CORS the data needs, and
  a guide; .gitea/workflows/site.yml builds on main and publishes with
  rsync when the SITE_* secrets are set.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

docs/glossary.md

@@ -1,6 +1,6 @@
 # Glossary
 
-A scientific paper changes after it is published: errata appear, readings get corrected, annotations pile up. manuspec is a set of file formats for scientific papers that keeps each sentence findable through those changes (repository: <https://git.scient.ing/infra/manuspec>).
+A scientific paper changes after it is published: errata appear, readings get corrected, annotations pile up. paperspec is a set of file formats for scientific papers that keeps each sentence findable through those changes (repository: <https://git.scient.ing/infra/paperspec>).
 This glossary defines its terms for readers from newcomer to expert, implementers included.
 Each entry gives the plain meaning, then the precise one, then the chapter that defines it.
 
@@ -59,7 +59,7 @@ Fidelity level
 JATS
 :   Outside term.
 Journal Article Tag Suite, ANSI/NISO Z39.96-2024, an XML format in which publishers and archives exchange journal content ([the NISO page](https://www.niso.org/publications/z3996-2024-jats)).
-In manuspec, `jats` is a witness kind: the fixture `okafor2025open` was established from a JATS file and a PDF that agree.
+In paperspec, `jats` is a witness kind: the fixture `okafor2025open` was established from a JATS file and a PDF that agree.
 The formats ingest JATS and do not replace it. ([2.3](../spec/02-model.md#23-witnessesjson))
 
 Keyed hash