[DREAM-802] Migrate phase definitions and export template lists to BorderBoxList

[myabc]

Ticket

https://community.openproject.org/wp/DREAM-802

What are you trying to accomplish?

Second slice of the DREAM-697 split: migrates the two admin surfaces whose markup gates DREAM-789, so the sortable-lists migration sequence under DREAM-671 can proceed once this lands.

• Settings::ProjectPhaseDefinitions::IndexComponent moves from border_box_container to OpenProject::Common::BorderBoxListComponent.
• WorkPackageTypes::ExportTemplateListComponent does the same, keeping its readonly Enterprise banner state and per-row toggles.
• The phase definitions list opts into empty_state_behavior: :dynamic: filtering to no matches now shows the blankslate inside the box, replacing the detached plain-text "No items found" notice.

What approach did you choose and why?

One commit per surface with component specs each, mirroring the review structure of the rest of the stack. Stacked on the DREAM-801 API PR (#24643) because both surfaces use the reworked menu and header slots.

Visual comparisons

Show baseline/candidate screenshots

Baseline is shown on the left; the candidate stack is shown on the right. (Screenshots predate the empty-state rework; regeneration pending.)

Project phase definitions

Work package type PDF export templates

Merge checklist

• Added/updated tests
• Added/updated documentation in Lookbook (patterns, previews, etc)
• Tested major browsers (Chrome, Firefox, Edge, ...)

[Copilot]

Copilot encountered an error and was unable to review this pull request. You can try again by re-requesting a review.

[myabc]

This will go soon.

[Copilot]

Copilot encountered an error and was unable to review this pull request. You can try again by re-requesting a review.

[github-actions]

Warning

Flaky specs

• rspec ./spec/features/activities/work_package/activities_spec.rb[1:5:2:1]

🤖 Ask Copilot to investigate

Copy the prompt below into a new comment on this PR to delegate the investigation to GitHub Copilot. It will look into the flakiness and open a separate pull request with you as reviewer.

@copilot The following spec(s) are flaky in CI (first seen on PR #24644, linked for reference only):

- `rspec ./spec/features/activities/work_package/activities_spec.rb[1:5:2:1]`

Treat this as a standalone task, unrelated to PR #24644. Create a new branch from origin/dev and open a new pull request targeting dev — do not stack it on PR #24644 or reuse that branch.

Follow the playbook in docs/development/testing/handling-flaky-tests/README.md to find the root cause and fix the underlying race — do not skip, delete, or weaken the spec to make it pass; disabling is a last resort per the playbook, and only with a bug ticket. Verify the fix by running the spec(s) repeatedly (e.g. `script/bulk_run_rspec --run-count 10`).

If you cannot reproduce the flake or are not confident in a fix after reasonable investigation, do not fabricate a change or skip the spec to force CI green. Instead, leave the pull request in draft and document what you tried, the suspected cause, and any leads in its description, then assign @myabc to take over.

Once the fix is verified, title the PR after the spec(s) it fixes, and use the PR description to explain the root cause, how the change resolves it, and the before/after results. Label the PR `flaky-spec`, assign @myabc, and request a review from @myabc.
On every commit, set @myabc as the sole co-author with a `Co-authored-by:` trailer (use their GitHub no-reply email so it links to their account), so it is traceable who dispatched the fix.

[bsatarnejad]

LGTM 👍🏼

[github-actions]

Warning

Flaky specs

• rspec ./modules/backlogs/spec/features/inbox_column_spec.rb[1:7:1]

🤖 Ask Copilot to investigate

Copy the prompt below into a new comment on this PR to delegate the investigation to GitHub Copilot. It will look into the flakiness and open a separate pull request with you as reviewer.

@copilot The following spec(s) are flaky in CI (first seen on PR #24644, linked for reference only):

- `rspec ./modules/backlogs/spec/features/inbox_column_spec.rb[1:7:1]`

Treat this as a standalone task, unrelated to PR #24644. Create a new branch from origin/dev and open a new pull request targeting dev — do not stack it on PR #24644 or reuse that branch.

Follow the playbook in docs/development/testing/handling-flaky-tests/README.md to find the root cause and fix the underlying race — do not skip, delete, or weaken the spec to make it pass; disabling is a last resort per the playbook, and only with a bug ticket. Verify the fix by running the spec(s) repeatedly (e.g. `script/bulk_run_rspec --run-count 10`).

If you cannot reproduce the flake or are not confident in a fix after reasonable investigation, do not fabricate a change or skip the spec to force CI green. Instead, leave the pull request in draft and document what you tried, the suspected cause, and any leads in its description, then assign @myabc to take over.

Once the fix is verified, title the PR after the spec(s) it fixes, and use the PR description to explain the root cause, how the change resolves it, and the before/after results. Label the PR `flaky-spec`, assign @myabc, and request a review from @myabc.
On every commit, set @myabc as the sole co-author with a `Co-authored-by:` trailer (use their GitHub no-reply email so it links to their account), so it is traceable who dispatched the fix.