Remove Binder links, switch to Colab-only, pin to workspace tag, then delete release branches

[Jammy2211]

Background

Follow-up to autolens_workspace#71 (default-branch-release-to-main). The release branch has been retired in favour of tagging on main and pinning each cloned workspace to its library version via version.txt. However, deletion of the release branches on origin is currently blocked because 50 files across 9 repos still reference them in user-facing Binder/Colab URLs of the form:

• https://mybinder.org/v2/gh/Jammy2211/<workspace>/release?filepath=...
• https://colab.research.google.com/github/Jammy2211/<workspace>/blob/release/<path>

Both URLs are also wrong on the owner axis: the workspace repos now live under PyAutoLabs/<workspace> and only resolve via GitHub's transferred-repo redirect.

Decision

1. Drop Binder entirely. Delete every mybinder.org/... URL across all 9 repos. Where a file currently has only a Binder link, replace it with the Colab equivalent. Where a file has both Binder and Colab side-by-side (|-separated in RST), strip the Binder part and tidy the separator.
2. Keep Colab only, and pin every Colab URL to the workspace tag that matches the latest released library version (currently 2026.4.13.6), under the PyAutoLabs owner. This mirrors the pip-install + clone-tagged-workspace contract: a "Try on Colab" click gives the user the workspace at the same version their installed library is on, reproducibly.
3. Make the release pipeline maintain the tag in those URLs so README links don't drift after every release.
4. Add a CI guard that fails the build if mybinder.org, Jammy2211/, or /blob/release/ reappear in any doc/README path under the affected repos.
5. Once merged and verified, delete the three release branches from origin.

Affected Repositories

• Libraries (READMEs + Sphinx docs + paper.md): PyAutoFit, PyAutoGalaxy, PyAutoLens
• Workspaces (READMEs + start_here.{ipynb,py} + howto chapter intros): autofit_workspace, autogalaxy_workspace, autolens_workspace
• PyAutoBuild (release.yml: tag-bumper step + CI guard workflow)
• euclid_strong_lens_modeling_pipeline (one README — bundle for convenience)

50 files in total identified via grep.

Implementation Steps

1. Audit the 50 files and classify each: Binder-only, Colab-only, both. Note any chapters where Colab equivalents don't yet exist (autofit howto chapters look Binder-only — need Colab URLs minted).
2. Land PyAutoBuild changes first:
   • New CI workflow that fails if forbidden patterns appear (mybinder.org, gh/Jammy2211/(autofit|autogalaxy|autolens)_workspace, /blob/release/).
   • New release-pipeline step that seds the version tag in every README/docs file under the 6 affected repos as part of the version bump commit. Use a literal current-tag string as the bump target so the diff is easy to audit.
3. Sweep the 6 workspace + library repos: rewrite all 50 files. Smoke-test by clicking the new Colab links manually (or curl-checking they resolve to a real notebook).
4. Sweep euclid_strong_lens_modeling_pipeline.
5. Smoke tests + readthedocs preview build to confirm Sphinx docs render correctly.
6. Open PRs (PyAutoBuild first, then the 6 README-bearing repos in parallel since they don't depend on each other), library-first merge gate.
7. Delete release from PyAutoLabs/{autofit,autogalaxy,autolens}_workspace.

Suggested branch

feature/release-url-sweep-and-tag-pinning

Affected repos

PyAutoFit, PyAutoGalaxy, PyAutoLens, PyAutoBuild, autofit_workspace, autogalaxy_workspace, autolens_workspace, euclid_strong_lens_modeling_pipeline

Notes

• PyAutoLens v1.15.x legacy tags are not relevant — workspace pinning uses the date-based 2026.x.x.x scheme, same as the others.
• Binder removal is irreversible from a user-experience standpoint. Confirmed acceptable in scoping conversation: simpler maintenance, single "Try in browser" surface, Colab is the de-facto target for ML/Python tutorials anyway.

[Jammy2211]

Shipped — 2026-04-18

PRs

• PyAutoBuild infrastructure: Add Colab URL guard + release-pipeline tag bumper PyAutoBuild#49
• PyAutoFit: Drop Binder URLs, pin Colab URLs to workspace tag 2026.4.13.6 PyAutoFit#1226
• PyAutoGalaxy: Drop Binder URLs, pin Colab URLs to workspace tag 2026.4.13.6 PyAutoGalaxy#356
• PyAutoLens: Drop Binder URLs, pin Colab URLs to workspace tag 2026.4.13.6 PyAutoLens#441
• autofit_workspace: Drop Binder URLs, pin Colab URLs to workspace tag 2026.4.13.6 autofit_workspace#34
• autogalaxy_workspace: Drop Binder URLs, pin Colab URLs to workspace tag 2026.4.13.6 autogalaxy_workspace#33
• autolens_workspace: Drop Binder URLs, pin Colab URLs to workspace tag 2026.4.13.6 #74
• euclid_strong_lens_modeling_pipeline: Drop Binder URLs, pin Colab URLs to workspace tag 2026.4.13.6 euclid_strong_lens_modeling_pipeline#2

Summary

All mybinder.org URLs across workspace + library docs/READMEs/papers/tutorials have
been replaced with equivalent Google Colab URLs. Every Colab URL is now pinned to the
date-based workspace tag 2026.4.13.6 (under owner PyAutoLabs, replacing legacy
Jammy2211). Binder badge images were swapped for Colab badges and the RST
|binder| substitution renamed to |colab|.

The release pipeline (PyAutoBuild #49) now invokes bump_colab_urls.sh <new-tag>
against every workspace and the three libraries on each release, so URLs advance
automatically. A new url_check.sh lives in PyAutoBuild/autobuild/ and is wired
into a .github/workflows/url_check.yml workflow in each of the seven affected
repos to fail CI if anyone reintroduces a mybinder.org URL, a Jammy2211/
Colab owner, or a /blob/release/ Colab ref.

With all URL references migrated off the workspace release branches, the three
workspace release branches were deleted from origin:

• PyAutoLabs/autofit_workspace/release (was 8b745c9)
• PyAutoLabs/autogalaxy_workspace/release (was fa0484a)
• PyAutoLabs/autolens_workspace/release (was 708d5ff)

Default branch on these repos is main (from #71). The release branch is no longer
needed — releases are tagged at canonical YYYY.M.D.B form, which is what users
clone after a pip install.

Session Notes

• Two third-party hits to Jammy2211/<ws>/blob/release/... will now 404 (the
  Jammy2211 repo redirect resolves to PyAutoLabs, but the deleted branch makes the
  full URL unresolvable). User-side cost was discussed when this task was scoped
  out of feat: switch workspace default branches from release to main with version-paired tags #71.
• The pending-release label did not exist on PyAutoLabs/PyAutoLens or
  Jammy2211/euclid_strong_lens_modeling_pipeline and had to be created via
  gh api -X POST repos/<owner>/<repo>/labels before the PR creation succeeded.
• Local gh does not support gh search code, so external-reference checks were
  done via gh api -X GET search/code directly (heavily rate-limited).
• Perl alternation pipe collides with s|...| delimiter — used s#...# throughout
  to avoid Unmatched ( in regex errors.
• The euclid_strong_lens_modeling_pipeline canonical checkout has 2 unpushed
  commits on local main predating this task that prevented pull --ff-only from
  succeeding. PR Add mass list arg for Galaxy #2 was merged cleanly and the feature branch was deleted; the
  unrelated unpushed work is left in place for the user to handle.