[peymanvahidi]

A new layout for the explore page: a top bar, a toolbar above the plot, and a sidebar on the right with the legend, filters, EAT and 3D structure. The sidebar can be folded away. The plot now fills the space it has.

Also in this PR:

• A redesigned filter: conditions as cards, plain-word choices, value lists with counts and search, and a range slider with a histogram for numbers.
• An EAT panel for annotations with predicted values: how much is predicted, a reliability chart with a cut-off, a breakdown by label, details for the clicked protein, and export of the IDs.
• Dark mode, support for phones and tablets, an updated product tour, and refreshed docs and screenshots.
• The Table (.tsv) export from main now sits in the new Export menu (under More on phones).

Builds on #526: merge that first. Use a merge commit, not squash.

Tests: unit, end-to-end (desktop and phone) and performance checks pass.

Follow-ups (not in this PR): a few large source files still need splitting, the core package's unit tests are not type-checked, and part of the legend code mixes row actions with sorting.

[peymanvahidi]

A review pass fixed 26 small issues: EAT filter undo and Dim saving, filter value counts inside groups, touch targets, keyboard focus, and a legend drag bug. All unit, end-to-end and performance checks pass.