Surface the per-game "single word" rule to the client and refine the
random-opponent New Game screen.
- Wire: thread multiple_words_per_turn into the GameView and Invitation
FlatBuffers tables (Go + TS regenerated), through pkg/wire builders and both
the backend push-event and gateway REST paths.
- In-game indicators (single-word games only): a small 1 in the status bar's
score-preview slot (yields to the live preview) and a centred "One word per
turn" label in the history-drawer header. Standard games show neither.
- Invitation card gains a "One word per turn" line for single-word invitations.
- Auto-match redesign: variant plaques are mutually-exclusive selects (highlight
on tap, no longer enqueue); a lone offered variant is pre-selected; a bottom
"Start game" button (disabled until a variant is chosen) confirms. The rule
toggle appears once a Russian variant is selected.
- Tests: e2e for the new auto flow and the in-game indicator (mock g3 is a
single-word game); mock/data + fixtures carry the new field. Docs: UI_DESIGN.