Prepare public release for Fall25 M4

[jlurien]

Problem description
PR for M4 should be ready by August 29th

Expected action

• Adjust versions and links in README, Changelog, yaml and feature files, using "public release" instead of "pre-release" for the new release. Adjust API Readiness checklist
• Double-check all requirements in the M4 review template

Additional context
Check that all pre-requirements are fulfilled:

• no PRs beside the release PR are waiting
• descriptions for date-time updated
• YAML files are correctly shown in viewers
• Check spelling