feat(v3.9.1): homepage — CKN notation, epoch self-progression, live capability; publish /ontology/v3.8/ runtime core

- Landing rewritten for CKP v3.9.1 (Critical Isolation): nine-strand
  awakening (χ ρ σ α γ π δ φ ε), the CKN declaration with a worked
  notation example, a measured epoch timeline v3.4 → v3.10, and the
  live artifact surface (pgCK v0.4.15, cklib v1.5.3, hello-kernel).
- /ontology/v3.8/{core.ttl,index.html}: the runtime core vocabulary at
  its stable namespace (11 classes, 8 SHACL seal-gate shapes) — makes
  …/ontology/v3.8/core#Task dereference. Closes the 404 in #1.
- llms.txt + sitemap.xml aligned to v3.9.1 status and the new namespace.

Author: styk-tv