UI: tab-bar navigation — drop the hamburger

Replace Menu.svelte (hamburger) everywhere with tab-bar navigation:
- Settings hub (SettingsHub) from the lobby ⚙️ tab: Settings/Profile/
  Friends/About as in-place tabs, back → lobby; the lobby ⚙️ badge counts
  incoming friend requests (invitations keep their own lobby section).
- Comms hub (CommsHub) from the move-history 💬: Chat/Dictionary tabs,
  back → game; Dictionary only while the game is active.
- Game menu items relocate into the open history: 🏁 leave / 📤 export in
  the header, 🤝 add-friend per opponent card, 💬 comms; unread chat is
  badged on the score bar + the 💬.
- TapConfirm (tap → fading ✅ → tap) replaces the Skip/Hint press-and-hold
  popovers and drives the add-friend confirm.
- Fix the move-history "jump": the slid board is inert and the stage can't
  scroll, so a swipe up genuinely closes the history.

Remove Menu.svelte + HoldConfirm.svelte. Docs: UI_DESIGN, FUNCTIONAL(+ru),
PRERELEASE. UI check/unit/build/bundle/e2e (Chromium+WebKit) all green.

docs/UI_DESIGN.md

@@ -23,16 +23,24 @@ Login uses `Screen`.
 
 - **Back**: a thin, compact `<` drawn from two rotated CSS borders (`Header.svelte`
   `.chev`) — lighter than a glyph.
-- **Hamburger**: a CSS three-bar (`Menu.svelte`), deliberately larger; opens a dropdown
-  of items (lobby: Friends/Profile/Settings/About; game: History/Chat/Check word, plus
-  *Export GCG* on a finished game and *Add to friends* per opponent, then Drop game). A
-  red count **badge** rides the hamburger (and the lobby *Friends* item) for pending
-  incoming friend requests + invitations; the same dot style serves any future
-  notification count.
+- **No hamburger**: navigation is entirely bottom tab bars (the former `Menu.svelte`
+  dropdown is gone — it fought the Telegram-fullscreen layout, where it had to be re-centred).
+  Destinations beyond the lobby live behind **hub screens** reached from a tab: a ⚙️
+  **Settings hub** (`screens/SettingsHub.svelte`, the lobby's ⚙️ tab) and an in-game
+  **comms hub** (`game/CommsHub.svelte`, the history's 💬). A hub owns one nav bar + one
+  bottom tab bar whose tabs switch its body **in place** (state, not navigation), so the
+  back control always returns to the hub's parent (Settings → lobby, comms → game). Settings
+  hub tabs: ⚙️ Settings / 👤 Profile / 🤝 Friends / ℹ️ About (Friends hidden for guests);
+  comms hub tabs: 💬 Chat / 🔎 Dictionary (Dictionary only while the game is active). The
+  routes `/settings|/profile|/friends|/about` and `/game/:id/{chat,check}` survive as hub
+  entry points (so a Telegram friend-code deep-link still lands on the Friends tab).
 - **Tab bar** (`TabBar.svelte`): square, borderless, evenly distributed buttons — a large
-  emoji icon over a tiny truncated label. A press highlights a rounded **square** behind
-  the icon (slightly larger than it) until release; spacing keeps adjacent labels from
-  touching. No text selection on nav / tab-bar / buttons (`user-select: none`).
+  emoji icon over a tiny truncated label (hub tabs are **icon-only**). A press highlights a
+  rounded **square** behind the icon; a hub's **selected** tab stays highlighted (a filled
+  square with an accent underline). A red count **badge** rides the icon's corner — on the
+  lobby ⚙️ tab and the hub's 🤝 Friends tab for pending incoming friend requests (invitations
+  keep their own lobby section), and on the Hint tab for the remaining count. No text
+  selection on nav / tab-bar / buttons (`user-select: none`).
 - **Screen transitions** (`App.svelte`): navigation slides directionally — a
   screen entered from the lobby flies in from the right; returning to the lobby reveals it
   from the left (back). Transitions are local (so they do not play on first load) and
@@ -71,8 +79,9 @@ Login uses `Screen`.
   hovering a dragged tile never jumps the board. On touch the first tile placement auto-zooms
   in centred on the target, and **holding a dragged tile over a cell ~1 s** auto-zooms there
   the first time. The swipe-to-open-history gesture stays dropped (it fought native scroll);
-  history opens from the menu or a tap on the players plaque (below). A **hint** auto-zooms
-  centred on the hint's placement, not the top-left.
+  history opens on a **tap of the score bar** and closes on a tap or an **upward swipe** of
+  the then-inert board (below). A **hint** auto-zooms centred on the hint's placement, not
+  the top-left.
 - **Placing & recall** (`Game.svelte`): a rack tile is placed by tap-then-tap or by
   dragging it onto a cell; while a dragged tile is carried over the board, the aimed-at empty
   cell is **highlighted as a drop target** (an accent ring). A pending tile is taken back by a
@@ -81,11 +90,21 @@ Login uses `Screen`.
   recalled tile returns to its original rack slot.
 - **Players plaque & history** (`Game.svelte`): the seats above the board share
   the width evenly; the seat whose turn it is is **raised** (a drop shadow on its sides)
-  while the others read **sunk in** (an inset shadow). A tap anywhere on the plaque toggles
+  while the others read **sunk in** (an inset shadow). A tap on the plaque toggles
   the **move history** — a fixed-height slide-down drawer whose bottom border (and its
   shadow) pins to the board as the board slides down, instead of tracking the table as
   moves accumulate; its scrollbar gutter is reserved so the centred word column does not
-  jitter. A move's row lists every word it formed (the main word first).
+  jitter. A move's row lists every word it formed (the main word first). While the history
+  is open the **slid board is inert** and the stage cannot scroll, so the whole board reads
+  as a **tap-or-swipe-up-to-close** surface — closing genuinely clears the open state (it no
+  longer merely scrolls the board out of view, which used to leave a stale-open state that
+  made a follow-up plaque tap "jump" the board). The drawer carries its own **header**: a 🏁
+  **Drop game** (or 📤 **Export GCG** on a finished game) at the left and the comms 💬
+  (badged with unread chat) at the right, icon-only. Each **opponent**'s card also gains a
+  🤝 **add-friend** control (non-guests; hidden once a friend, disabled once requested) that
+  confirms via the fading-✅ tap, swapping the card's score for "Add friend?" while armed
+  (see Controls); the name and score stay centred — the 🤝 is pinned to the card's edge.
+  Unread chat is also badged on the score bar itself, so it shows with the history closed.
 - **Vertical fit & keyboard**: when the game does not fit the viewport, only the
   board area scrolls vertically (`Screen` `column` mode; the score bar, status, rack and tab
   bar stay fixed), while zoom keeps its own scroll. The check-word dialog opens in
@@ -107,9 +126,12 @@ Login uses `Screen`.
 
 ## Controls
 
-- **HoldConfirm** (`components/HoldConfirm.svelte`): the shared press-and-hold control. A
-  short tap opens a small popover above the button; a ~0.7 s hold runs the primary action
-  immediately. Used by the **Skip** and **Hint** tabs (each confirmed by an **Ok ✅** popover).
+- **TapConfirm** (`components/TapConfirm.svelte`, logic in `lib/tapconfirm.ts`): the shared
+  tap-to-confirm control. A first tap arms a ~2 s window showing a **fading ✅** (no fade
+  under reduce-motion, but the window still holds); a tap on the ✅ within it confirms,
+  otherwise it reverts. Used by the **Skip** and **Hint** tabs (the icon morphs to ✅, no
+  label — replacing the old press-and-hold popover) and the in-game **add-friend 🤝**. The
+  **Drop game** action keeps its `Modal` confirmation (a destructive, less-frequent action).
 - **MakeMove / Reset**: when ≥1 tile is pending the rack collapses its used slots
   and shifts left, a **borderless ✅ icon button** (styled like a tab, not a filled accent
   button) beside the rack commits the move — no popover, and disabled while the pending word
@@ -140,7 +162,11 @@ IV 🏅; active games show Your move 🟢 / Opponent's move ⏳; invitations use
 
 ## Social, account & history surfaces
 
-- **Friends** (`screens/Friends.svelte`, from the lobby menu): an "add a friend" block
+- **Settings hub** (`screens/SettingsHub.svelte`, the lobby ⚙️ tab): one nav bar + a bottom
+  tab bar over four bodies — ⚙️ Settings, 👤 Profile, 🤝 Friends, ℹ️ About — switched in
+  place; back always returns to the lobby. Guests see all but Friends. The lobby ⚙️ badge and
+  the 🤝 tab badge both show the pending incoming-friend-request count.
+- **Friends** (`screens/Friends.svelte`, the Settings hub's 🤝 tab): an "add a friend" block
   pairing a code **input** with a **Show my code** action that reveals a large 6-digit
   code + its expiry; then the incoming **requests** (Accept / Decline), the **friends**
   list (Remove / Block), and a **blocked** list (Unblock). Durable accounts only — a
@@ -163,12 +189,12 @@ IV 🏅; active games show Your move 🟢 / Opponent's move ⏳; invitations use
   the icon copies it. Flex text inputs carry `min-width:0` so they shrink instead of
   overflowing in Safari.
 - **History / GCG**: the in-game slide-down history gains the running total per move;
-  *Export GCG* shares or downloads the `.gcg` file and appears only once the game is
-  finished.
-- **Finished game**: the board keeps no last-word highlight and no zoom; the menu drops
-  *Check word* and *Drop game*; and the footer (rack + tab bar) is **drawn but inert**
-  (greyed, non-interactive) rather than hidden, so the layout does not jump. Chat
-  send / nudge are the ⬆️ / 🛎️ icons.
+  *Export GCG* (the 📤 in the history header) shares or downloads the `.gcg` file and
+  appears only once the game is finished.
+- **Finished game**: the board keeps no last-word highlight and no zoom; the history header
+  offers *Export GCG* (not *Drop game*) and the comms hub hides the 🔎 *Dictionary* tab; and
+  the footer (rack + tab bar) is **drawn but inert** (greyed, non-interactive) rather than
+  hidden, so the layout does not jump. Chat send / nudge are the ⬆️ / 🛎️ icons.
 
 ## Caveat