[xispa]

Description of the issue/feature this PR addresses

Analysis services that define result variables (interim fields) contribute extra columns to the analyses listing. These columns are dynamic: they don't exist in the static column set and are created server-side only while building the folderitems, then inserted at the Result/AdditionalValues position of each review_states[].columns.

The ReactJS listing, however, derives the visible column order from the localStorage-backed merged config (_merged_column_config → merge_column_config), which:

1. tail-appends any server key not present in the stored config, in columns-dict key order — and dynamic columns sit last in that dict; and
2. uses review_states[].columns (the correctly-ordered list) only as a membership set for the visibility filter, never for ordering.

As a result the columns are visible but always ordered last. A second, related defect: resetColumns restores @state.columns from @root_el.dataset.columns — the page-render DOM snapshot captured before the folderitems ran — which contains none of the dynamic columns.

Reproducible with any service that has result variables (independent of result type or add-on).

Current behavior before PR

• Result-variable columns always render at the far right of the listing, off-screen until the user scrolls — regardless of the configured Sample view analysis columns order.
• Clicking Reset columns makes the result-variable columns disappear entirely.

Desired behavior after PR is merged

• Result-variable columns render in their server-defined slot (e.g. immediately before Result), honoring review_states[].columns.
• Reset columns restores server defaults without dropping the dynamic columns.

Changes

• merge_column_config inserts a server key absent from the stored config at its server-defined position — right after its nearest already-placed server neighbor (front if none) — instead of tail-appending. Genuinely-trailing add-on columns still land at the end; mid-list columns land in their slot. The caller must therefore pass server_columns in the intended display order.
• _merged_column_config feeds the review-state column order into the merge (the columns dict alone can't express mid-list placement, since dynamic columns are keyed last).
• resetColumns re-renders from the live @state.columns rather than the stale dataset.columns snapshot.
• Added column_config unit tests for mid-list insertion, multiple new keys, leading key, and anchor-under-user-reorder. Rebuilt bundle.

--
I confirm I have tested the PR thoroughly and coded it according to PEP8
standards.

[ramonski]

Thanks! Encountered that but as well recently