Add deck synergy suggestions, a responsive deck layout, and undoable library bulk-add

Suggestion scoring is fully offline (tribal/mechanic/archetype/mana-base
signals derived at ingest, no external synergy database), with an "unusual
picks" mode that surfaces underappreciated cards instead of staples. The
deck page's top panels now use a CSS grid so wide windows don't waste
horizontal space. Library's bulk add-to-deck can clobber existing deck
quantities, so it now offers an undo (snackbar + command palette, the
latter with no timeout) that restores each card's prior state exactly.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

src-tauri/src/lib.rs

@@ -41,6 +41,7 @@ pub fn run() {
             commands::set_deck_commander,
             commands::set_deck_card,
             commands::deck_contents,
+            commands::suggest_cards,
             commands::card_decks,
             commands::export_deck,
             commands::import_deck,