Add the Independent Proof LLC holding page

A one-page "notice of preparation" in a certificate style: the company is
in preparation, there is nothing to do yet, the domain is not for sale,
and unsolicited inquiries are not accepted. It carries no contact details
of any kind, and search engines are told to stay away (noindex meta and
robots.txt).

Fonts are self-hosted with their OFL licences, and the seal and guilloche
border are static SVG, so the page makes no third-party requests and needs
no script. The build copies public/ to dist/, and the Start9 Pages deploy
uses the same NextExplorer script as the YPBA site.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_012NBdmeSPq4bFCSE1urk99W

TODO.md

@@ -0,0 +1,21 @@
+# TODO
+
+## Before the public launch of the holding page
+
+- [ ] Choose the cloud host. Deploy to it the same way for this site and the YPBA site: each repo
+      builds `dist/`, and one deploy command per host sends it (for example rsync or SFTP over SSH,
+      with the host and user in the git-ignored `deploy.local.env`).
+- [ ] Point independentproofllc.com (apex and `www`) at the host, with HTTPS.
+- [ ] Make independentproofllc.org and `www.independentproofllc.org` answer with a permanent (301)
+      redirect to https://independentproofllc.com, so the site has one address.
+- [ ] Before either domain gets mail records, decide on email. Avoid a catch-all mailbox: spammers
+      guess addresses like `info@`.
+
+## Later
+
+- [ ] Brand: logo, colours and typefaces. The seal on the holding page is a placeholder.
+- [ ] Favicon (the page currently tells browsers there is none).
+- [ ] Build out the real site in this repo. Its output still goes to `dist/`, so the deploy
+      commands keep working.
+- [ ] Decide when search engines may index the site; then remove the `robots` meta tag and change
+      `public/robots.txt`.