v0.1: contract legal overhaul + Grav site + e-sign integration

- Real dispute-resolution/governing-law/venue section replaces the
  unenforceable 'auto resolved in our favor' clause; jury waiver
  rewritten with carve-outs
- New sections: definitions, liability cap, confidentiality, IP,
  force majeure, assignment, notices, termination/renewal, e-sign
- SLA/SLO semantics fixed (SLA=contractual min, SLO=non-binding
  target); payment currency/invoicing terms added
- Introduction now mustache-templated ({{PARTY2}} bug fixed)
- SUMMARY.md structure fixed (case mismatch, empty heading, dupes)
- RenderBook.sh build-only; new RenderSite.sh renders Grav pages
  (site/) incl. DocuSeal e-sign page via APISIX

Ticket: https://projects.knownelement.com/issues/924

contract-inputs/sign-electronic.md

@@ -0,0 +1,55 @@
+---
+title: 'Sign Electronically'
+visible: true
+---
+
+## Sign this contract electronically
+
+This contract can be executed electronically via the KNEL DocuSeal e-signature platform, reached through the KNEL APISIX API gateway. Enter the signer's details below; DocuSeal will email a signing link.
+
+<form id="esign-form" onsubmit="return esignSubmit(event)">
+  <label for="esign-name">Full name</label>
+  <input type="text" id="esign-name" name="name" required style="display:block;margin-bottom:8px;min-width:280px;padding:6px;">
+  <label for="esign-email">Email address</label>
+  <input type="email" id="esign-email" name="email" required style="display:block;margin-bottom:12px;min-width:280px;padding:6px;">
+  <label for="esign-entity">Entity (Party 2)</label>
+  <input type="text" id="esign-entity" name="entity" required style="display:block;margin-bottom:12px;min-width:280px;padding:6px;">
+  <button type="submit" style="padding:8px 16px;">Request signature link</button>
+</form>
+
+<p id="esign-status" style="margin-top:12px;"></p>
+
+<script>
+function esignSubmit(ev) {
+  ev.preventDefault();
+  var status = document.getElementById('esign-status');
+  status.textContent = 'Requesting signing link…';
+  var name = document.getElementById('esign-name').value;
+  var email = document.getElementById('esign-email').value;
+  var entity = document.getElementById('esign-entity').value;
+  fetch('{{ESIGN_API_URL}}', {
+    method: 'POST',
+    headers: {'Content-Type': 'application/json'},
+    body: JSON.stringify({
+      template_id: Number('{{ESIGN_TEMPLATE_ID}}'),
+      submitters: [
+        {email: email, name: name, role: 'First Party'},
+        {email: email, name: name + ' (' + entity + ')', role: 'Second Party', is_invited: false}
+      ]
+    })
+  }).then(function (r) {
+    if (!r.ok) throw new Error('gateway returned ' + r.status);
+    return r.json();
+  }).then(function (data) {
+    var slug = data.submitters && data.submitters[0] && data.submitters[0].slug;
+    if (slug) {
+      window.location.href = 'https://esign.knownelement.com/s/' + slug;
+    } else {
+      status.textContent = 'Signing request created. Check ' + email + ' for the signing link.';
+    }
+  }).catch(function (e) {
+    status.textContent = 'Could not create the signing request (' + e.message + '). Contact KNEL helpdesk.';
+  });
+  return false;
+}
+</script>