feat(social): per-game friend request to disguised robots + lobby/stats/tile cosmetics

Functional: the in-game add-friend handshake aimed at an auto-match opponent who is
secretly a pooled robot now records the request per (game, seat) in a new
robot_friend_requests table -- never against the shared robot account -- mirroring the
robot_blocks pattern. The shared account stays out of friendships, the "requested" state
is pinned to the seat (not leaked across the player's other games), the robot ignores it,
and a background reaper drops the row 7 days after its game finishes. The outgoing-requests
list carries these per-game rows so the seat control stays disabled across reloads. No
withdraw UI, per owner decision.

Cosmetics:
- Lobby: an in-progress game tints the viewer's own score number green when leading or
  tied, red when trailing (reusing --ok/--danger); scores now render in seat-number order,
  matching the over-the-board scoreboard.
- Stats: the per-variant best move is laid out on two lines -- the variant label, then the
  score (right-aligned in its column) and the word tiles (left-aligned) below it.
- Dark theme: the played-tile background is a touch darker so a player-placed tile reads
  with more contrast (light theme unchanged).

Docs (ARCHITECTURE, FUNCTIONAL + _ru mirror, backend README, UI_DESIGN) updated in the
same change.

docs/UI_DESIGN.md

@@ -237,7 +237,11 @@ and a long message does not scroll.
 
 Lobby rows show two lines (opponents, then result + score) with a large place-based emoji
 on the right: Victory 🏆 / Defeat 🥈 / Draw 🏅, and for 3–4-player games II 🥈 / III 🥉 /
-IV 🏅; active games show Your move 🟢 / Opponent's move ⏳; invitations use 💌. When a listed
+IV 🏅; active games show Your move 🟢 / Opponent's move ⏳; invitations use 💌. The score line
+lists seats in **seat-number order** (matching the over-the-board scoreboard); on an
+**in-progress** game the viewer's **own** number is tinted `--ok` when leading or tied and
+`--danger` when trailing (other numbers stay muted; no bold), a quick "am I ahead" read that
+finished games leave to the place emoji. When a listed
 game **becomes your turn or finishes** while the lobby is open, that status emoji **blinks
 twice** (a two-cycle opacity fade, ~2 s; suppressed under reduce-motion) to draw the eye — the
 opponent's-turn change is silent. Each card's blink is keyed by game id, so overlapping
@@ -294,11 +298,11 @@ enabled on the first, uncached load) and flip in place when an event refreshes t
   pure numbers, no charts; hint-share is a one-decimal percentage in the active locale's
   notation (e.g. "4.8%" / "4,8%") — followed by a **full-width "best move" card** that
   breaks the best move
-  down per variant: one row per played variant (catalogue order, empty variants
-  omitted) with the variant name on the left, the **word drawn as game tiles**
+  down per variant: two lines per played variant (catalogue order, empty variants
+  omitted) — the variant name on its own line, then below it the score (right-aligned
+  in a shared column so the scores align) and the **word drawn as game tiles**
   (`components/WordTiles.svelte`, the board's placed-tile look at a small fixed size;
-  a wildcard shows its letter but no value) right-aligned to a shared edge, and the
-  score right-aligned in its own column.
+  a wildcard shows its letter but no value) left-aligned, so long words get the full width.
 - **Profile editing** (`screens/Profile.svelte`): an inline form — display name, a
   **UTC-offset** timezone dropdown (defaulting to the browser's offset), the away
   window as hour + 10-minute dropdowns (24-hour, ≤ 12 h), and block toggles — plus an