Closes gh-26876

Closes gh-26875

Closes gh-26852

Closes gh-26874

Closes gh-26873

Closes gh-26855

* pr/26001:
  Polish "Add auto-configuration for DiskSpaceMetrics"
  Add auto-configuration for DiskSpaceMetrics

Closes gh-26001

See gh-26001

See gh-26001

Closes gh-26871

Closes gh-26870

Closes gh-26857

Closes gh-26869

Closes gh-26868

Closes gh-26856

Closes gh-26723

* gh-26861:
  Update some more references to 2.5.x

Closes gh-26861

See gh-26861

Add `SpringApplicationShutdownHook` to manage orderly application
shutdown, specifically around the `LoggingSystem`. `SpringApplication`
now offers a `getShutdownHandlers()` method that can be used to add
handlers that are guaranteed to only run after the `ApplicationContext`
has been closed and is inactive.

Fixes gh-26660

Fixes gh-26850

Closes gh-26846

Closes gh-26845

Closes gh-26764

* pr/26816:
  Polish "Fix Optaplanner starter url"
  Fix Optaplanner starter url

Closes gh-26816

See gh-26816

See gh-26816

Closes gh-26843