Investigate: Remove dev_containers.zip Workflow

IMPLEMENTATION RULES: Before implementing this plan, read and follow:

WORKFLOW.md - The implementation process

PLANS.md - Plan structure and best practices

Status: ✅ Completed (2026-04-08, implemented via PLAN-remove-zip-workflow.md)

Goal: Remove the unused dev_containers.zip creation and GitHub release from the CI pipeline.

Priority: Low — no user impact, just CI cleanup

Last Updated: 2026-04-07

Problem

The zip_dev_setup.yml workflow creates dev_containers.zip and publishes it as a GitHub release on every successful CI run. But nothing downloads this zip anymore:

install.sh downloads devcontainer-user-template.json directly from GitHub (not from the zip)
install.ps1 does the same
dev-sync was removed (it was the only consumer of the zip)

~~The workflow still does two useful things that should be preserved:~~

Update (2026-04-07): Further analysis shows the ENTIRE workflow is a no-op:

install.sh already has REPO="helpers-no/devcontainer-toolbox" hardcoded (line 6)
install.ps1 already has $repo = "helpers-no/devcontainer-toolbox" hardcoded (line 8)
TOOLBOX_REPO_PLACEHOLDER no longer exists in either file
The CI replacement step replaces nothing, the commit step commits nothing

The entire workflow can be deleted. Nothing to keep, nothing to rename.

Questions to Answer

1. Is copy-mode still supported?

ANSWERED: No. All users use the pre-built image. Copy-mode (clone repo + build from Dockerfile.base) is only for DCT contributors developing the toolbox itself.

This means .devcontainer/.version can be fully removed — no users depend on it.

2. Does `version-utils.sh` work without `.devcontainer/.version`?

ANSWERED: Yes, with one fix. The fallback chain works:

~~.devcontainer/.version~~ — will be removed
$DCT_HOME/version.txt — image-mode (works, this is the primary path)
../version.txt — dev devcontainer (works)

But TOOLBOX_REPO is only set from .devcontainer/.version. Without it, _check_for_updates() can't check GitHub for newer versions.

Fix: Hardcode TOOLBOX_REPO as fallback. It's always helpers-no/devcontainer-toolbox. No one forks DCT, and if they did they'd need to change many things anyway.

3. What about `website/docs/contributors/ci-cd.md`?

ANSWERED: Delete it. ci-pipeline.md (created today) replaces it with current, accurate documentation.

4. Does Docusaurus use `.devcontainer/.version`?

ANSWERED: No. Docusaurus reads version.txt (repo root, single version number) at build time via docusaurus.config.ts. The .devcontainer/.version file (key-value format with VERSION/REPO/UPDATED) is a completely separate file only used by version-utils.sh.

4. Files that reference the zip (code, not docs)

File	Reference	Action needed
`.github/workflows/zip_dev_setup.yml`	Creates the zip	Simplify workflow
`.devcontainer/manage/lib/version-utils.sh`	Reads `.devcontainer/.version`	Add `TOOLBOX_REPO` fallback
`website/docs/contributors/ci-cd.md`	Documents the zip	Delete or update
`website/docs/contributors/ci-pipeline.md`	Documents Workflow 3	Update
`website/docs/contributors/releasing.md`	References zip + release	Update
Completed plans (6 files)	Historical references	No changes needed

Next Steps

Status: ✅ Completed (2026-04-08, implemented via PLAN-remove-zip-workflow.md)
Problem
Questions to Answer
Next Steps

Status: ✅ Completed (2026-04-08, implemented via PLAN-remove-zip-workflow.md)​

Problem​

Questions to Answer​

1. Is copy-mode still supported?​

2. Does version-utils.sh work without .devcontainer/.version?​

3. What about website/docs/contributors/ci-cd.md?​

4. Does Docusaurus use .devcontainer/.version?​

4. Files that reference the zip (code, not docs)​

Next Steps​