v0.7.0

Added

• Matrix environment-column controls. Per-user control over the matrix's environment columns: a Columns picker (matrix view) to show/hide individual environments — a hidden column is removed from the grid entirely — and drag-to-reorder of the column headers via a grip handle. The Fields and Columns buttons show a count badge when items are hidden, and "Show all · reset order" restores the defaults. Column order and visibility persist client-side and survive reloads. No API or contract change — the matrix response still carries every environment; this is purely a per-user view preference.