fix stable release pr version race

[tarik02]

What Changed

• Run the release PR workflow after the release workflow completes instead of directly on main pushes.
• Skip the workflow-run path when the release workflow fails.
• Fetch tags before resolving stable release metadata.
• Document the fork release PR sequencing.

Why

The release PR workflow could run on the stable release merge before the release workflow had published the matching tag. That allowed it to recreate a PR for an already released version. Running after release publication makes tag-based version resolution see the latest stable tag, so the next release PR advances to the next version.

Checklist

• This PR is small and focused
• I explained what changed and why
• I included before/after screenshots for any UI changes
• I included a video for animation/interaction changes