docs: remove orphaned placeholder pages

Several documentation pages carried over from the docs-page and
scs-docs subtree merges were never wired into the consolidated
sidebar. They contained only a heading and a "TODO" placeholder and
were unreachable: no sidebar entry, no inbound links, and not covered
by any autogenerated directory.

Delete the 17 dead placeholder pages under the IaaS overview,
Container Layer (overview, deployment example A, guide1) and Operating
SCS (overview plus the monitoring, incident-management, audits,
lifecycle-management and logging sections) trees.

Strip the now-dangling references from sidebarsDocs.js: the Container
Layer Overview, Deployment Examples and Guides categories held nothing
but commented-out entries pointing at the deleted files, so they would
have rendered as empty generated-index pages; remove them along with
the commented-out operating-scs/overview entry. The Container Layer
category now resolves directly to Components, its only populated
subsection.

No real content is removed and no live link or sidebar entry referenced
any of these files, so the build is unaffected.

DocImpact
Assisted-by: Claude:claude-opus-4-8
Signed-off-by: Jan Klare <klare@osism.tech>

Author: jklare