docs(deck): refresh all eight decks, gate their text copies (S12)

[patterncatalyst]

S12 of the modernization plan: every deck in lgtm-presentation/ reviewed and refreshed in place.

Decks

• Six language decks: versions match the S2–S8 pins, code slides follow examples/, Appendix R (minikube) added, no Appendix S slides, vendor-neutral (no cloud SDKs, ACS or OpenShift reliance), professional voice, every slide has notes.
• K8s-Environment-Access-Policies (kubeconform) and Network-Policy-Process-Advisory (reworked to upstream Kubernetes + open source: NetworkPolicy/AdminNetworkPolicy, Cilium/Calico, Kyverno/Gatekeeper, Trivy, Falco), with their .md/.docx companions.
• Toolkit: scripts/deck_text.py, deck_edit.py, deck_render.sh, deck_fit.py; edit files under lgtm-presentation/edits/; Markdown text copies under lgtm-presentation/text/.

CI gate (content-ok): deck_text.py --check; the voice scan, positional, old-engine and stale-stack denylist checks now cover lgtm-presentation/ Markdown. Scanner re-vendored from lgtm-skills a93f128.

Examples fixed (found while aligning slides; verify.sh green in all six languages on Docker Engine):

• demo-01: /readyz answers 503 when the database is down (13/13).
• demo-21: async-signal-safe C++ handler; every language drains on a single SIGTERM (17/17).
• demo-25: write-back answers 202, upserts, and retries failed flushes with a bound (29/29).

Site: codetabs aligned with the examples (valet key, claim check, bulkhead, write-back, serdes, Apicurio v3 API, shutdown, readiness), vendor-neutral wording, figure fixes.

Validation: validate_site.py 0 errors, voice ban tier 0, deck_fit 0 flags, colour and caps audits 0 on every deck; watch-tier survivors recorded in _plans/s12-manifest/README.md.

Next: S13 (idiomatic persistence: Panache, Spring Data JPA, EF Core).