Add final results modal, active rules display, and UI improvements

- Add big final results modal at game end with rankings and share button
- Add active rules bar showing enabled variants during gameplay
- Increase spacing between player cards and opponents row
- Add Wolfpack bonus rule (2 pairs of Jacks = -5 pts)
- Change joker options to radio buttons (None/Standard/Lucky Swing/Eagle-Eye)
- Update Eagle-Eye jokers: +2 pts unpaired, -4 pts paired
- Add card flip animation on discard pile
- Redesign waiting room layout with side-by-side columns
- Style card backs with red Bee-style diamond crosshatch pattern
- Compact standings panel to show top 4 per category
- Various CSS polish and responsive improvements

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

server/RULES.md

@@ -116,7 +116,6 @@ Our implementation supports these optional rule variations:
 |--------|--------|
 | `lucky_swing` | Single Joker worth **-5** (instead of two -2 Jokers) |
 | `super_kings` | Kings worth **-2** (instead of 0) |
-| `lucky_sevens` | 7s worth **0** (instead of 7) |
 | `ten_penny` | 10s worth **1** (instead of 10) |
 
 ## Bonuses & Penalties
@@ -128,13 +127,11 @@ Our implementation supports these optional rule variations:
 | `tied_shame` | Tying another player's score = **+5** penalty to both |
 | `blackjack` | Exact score of 21 becomes **0** |
 
-## Gameplay Twists
+## Special Rules
 
 | Option | Effect |
 |--------|--------|
-| `queens_wild` | Queens match any rank for column pairing |
-| `four_of_a_kind` | 4 cards of same rank in grid = all 4 score 0 |
-| `eagle_eye` | Paired Jokers score **-8** (instead of canceling to 0) |
+| `eagle_eye` | Jokers worth **+2 unpaired**, **-4 paired** (spot the pair!) |
 
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