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/walkthrough.md

@@ -7,7 +7,7 @@ Its problems are modeled on the failures that the specification's rules address.
 Three readers can use the guide, and each gets something different.
 A newcomer knows what a paper and a citation are, not hashes or JSON, so every term is defined where it first appears.
 An implementer who will write a reader, writer, converter or checker gets the chapter and test vector for each step.
-An expert gets the status: [manuspec](https://git.scient.ing/infra/manuspec) is at version 0.1.0, and each format is `candidate` or `provisional` in [`registry/formats.json`](../registry/formats.json) (18 candidate, 11 provisional).
+An expert gets the status: [paperspec](https://git.scient.ing/infra/paperspec) is at version 0.1.0, and each format is `candidate` or `provisional` in [`registry/formats.json`](../registry/formats.json) (18 candidate, 11 provisional).
 The `scienting-` prefix on format names, as in `scienting-doc/1`, is the formats' namespace.
 It has nothing to do with the repository's name.
 
@@ -132,7 +132,7 @@ The table shows how each anchor resolves at revision 12 ([vectors/resolve.jsonl]
 A reader shows each note by its result.
 A checker of exact words accepts only `current`, `moved` and `reattached`.
 
-The [W3C Web Annotation Data Model](https://www.w3.org/TR/annotation-model/) is the general W3C Recommendation for annotating web resources. manuspec's annotation layers build on it, with a custom `AnchorSelector` followed by a standard `TextQuoteSelector` as a fallback.
+The [W3C Web Annotation Data Model](https://www.w3.org/TR/annotation-model/) is the general W3C Recommendation for annotating web resources. paperspec's annotation layers build on it, with a custom `AnchorSelector` followed by a standard `TextQuoteSelector` as a fallback.
 It has no permanent IDs for sentences inside the source, no hashes of the target text, and no results such as `moved` or drift.
 See [comparison.md](comparison.md).