Add President and Golf

Two more games on the existing framework — no changes were needed to the
lobby, networking, settings or update layers, which is what the shared
GameRules/GameAi contract was for.

President
- Threes low, twos high. Lead any number of one rank; follow with the
  same count of a higher rank, or pass. When everyone has passed the
  pile comes down and the last player to play leads again.
- Toggles: player count, rounds, twos clear the pile, four of a kind
  bombs, and the between-round card exchange.
- Plays are offered as whole sets rather than by selecting cards. A set
  is the unit of the game, so choosing from the legal sets is both
  easier to operate and impossible to get wrong.

Golf
- 4, 6 or 9 card grids. Draw from stock or discard, then either swap the
  card in or — only if it came off the stock — throw it and turn one of
  your own over. A card taken from the discard pile has to be used.
- Matching columns cancel to nothing; on the 3x3 board rows do too, but
  not on the shallower grids where three cards are not a line.
- Face-down cards are hidden from everyone including their owner, which
  is the point of the game: viewFor masks them with a fixed placeholder
  so the real card never reaches the device that has not turned it over.

Both engines are pure Kotlin and unit tested — 71 tests now, covering
ranking, legal moves, pile and hole resolution, scoring, redaction, wire
round-trips, and full random and AI playthroughs. The Golf test also
checks the AI actually beats random play rather than merely being legal.

Also widened the setup screen's option chips to wrap: the reveal-count
row carries up to ten, and a chip off the edge of the screen is a
setting that cannot be changed — the same failure as the Euchre Pass
button.

Co-Authored-By: Claude Opus 5 <[email protected]>
Claude-Session: https://claude.ai/code/session_015qjfMiPUDshdKEUa6vxqzN

docs/RULES-president.md

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+# President — implemented rules
+
+Also called Scum, Landlord, and a good deal worse. This is the ruleset the
+engine enforces. Anything marked **toggle** is in the game setup screen.
+
+## Table
+
+- 3 to 7 players — **toggle**. Everyone plays for themselves.
+- The whole 52-card deck is dealt out round-robin, so hands differ by at most
+  one card. There is no kitty and nothing is held back.
+
+## Ranking
+
+Threes are low and twos are high:
+
+```
+3 4 5 6 7 8 9 10 J Q K A 2
+```
+
+Suits are irrelevant. A card only ever competes on rank.
+
+## Play
+
+The player holding the lowest card leads the first round; afterwards the
+previous round's Scum leads.
+
+- **Leading.** Play any number of cards of the same rank — a single, a pair, a
+  triple, four of a kind. That count sets the size of the set for this pile.
+- **Following.** Play the same number of cards, all of one rank, of a strictly
+  higher rank. Or pass.
+- Passing does not put you out of the round, only out of this pile.
+- When everyone still holding cards has passed, the pile is taken down and
+  whoever played last leads a fresh one.
+
+**Twos clear the pile — *toggle*, on by default.** A set of twos beats anything
+regardless of rank, takes the pile down, and the player who threw it leads
+again.
+
+**Four of a kind bombs — *toggle*, off by default.** Four matching cards beat
+anything, whatever is on the pile, and clear it the same way.
+
+## Going out
+
+Shed your last card and you are out, taking the next free finishing position:
+President first, then Vice President, down through the Citizens to Vice Scum and
+Scum. The round ends when only one player still holds cards — they are the Scum.
+
+Going out on a pile-clearing set does not let you lead the next pile; the lead
+passes to the next player still in.
+
+## Scoring
+
+Finishing position scores `playerCount - 1 - position`, so in a four-hand game
+the President takes 3, the Vice President 2, Vice Scum 1 and the Scum nothing.
+Highest total after the last round wins — **toggle** for 3, 5 or 7 rounds.
+
+## Card exchange — *toggle*, on by default
+
+Between rounds the Scum hands their two best cards to the President, and the
+President hands two of their worst back.
+
+**Simplification:** the President's return is automatic — their two lowest
+cards. The fuller rule lets the President choose which two to give back, which
+would need a phase of its own; that is not implemented.
+
+## Known simplifications
+
+- No eights-stop, no revolution, no jokers, no suit-based tie-breaks.
+- The exchange is always two cards, rather than scaling with position.