Closes gh-27204

Closes gh-27206

Closes gh-27196

A side effect of 71995a90 caused the
dynamic table of contents in the left-hand side navigation to no longer
be displayed, likely due to the missing "details" DIV.

This commit addresses this issue by applying the custom header only to
index.adoc.

Consequently, the TOC is now displayed again on all pages except the
index page, but the customized header is no longer applied to those
pages.

We may revisit this issue if we decide that we want the custom header
on all pages (and not just the index page).

Closes gh-27177

See gh-27097

Closes gh-27156

Closes gh-27097

Closes gh-27110

Closes gh-27158

This commit adds a note to the documentation saying that ResourceBundle
does not support multiple bundles with the same base name.

Closes gh-27038

See gh-27075

Closes gh-27153

Closes gh-27122

This commit uses the target type where getRemoteAddress and
getLocalAddress are defined.

See gh-27120

Closes gh-26719

Closes gh-27161

Closes gh-26826

Closes gh-26999
See gh-26826

Closes gh-27081

Closes gh-27027

Closes gh-27120

Closes gh-27160

See gh-27158

Closes gh-27157

* pr/27155:
  Add Javadoc since to BeanDefinitionBuilder.setSynthetic()

Closes gh-27155

See gh-27155

* pr/27151:
  Fix link to Javadoc API
  Fix link to Javadoc API

Closes gh-27151

See gh-27151

See gh-27151

Closes gh-27068

Closes gh-27121

Closes gh-27132

See gh-26700

If the ThreadPoolTaskExecutor is dynamically changed with an invalid value
the state of the ThreadPoolTaskExecutor does no longer correctly represent
the state of the underlying ThreadPoolExecutor