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

site/05.execution/page.md

@@ -0,0 +1,27 @@
+---
+title: 'Execution'
+visible: true
+---
+## Execution
+
+IN WITNESS WHEREOF, the parties have executed this contract as of the Effective Date.
+
+### For Known Element Enterprises LLC
+
+- Name: ______________________________
+- Title: ______________________________
+- Signature: ______________________________
+- Date: ______________________________
+
+### For TSYS Group Component
+
+- Name: ______________________________
+- Title: ______________________________
+- Signature: ______________________________
+- Date: ______________________________
+
+### Electronic execution
+
+This contract may be executed electronically via the KNEL e-signature platform:
+
+[Sign this contract electronically](https://contract.knownelement.com/sign)