Add app shell with Euchre and Sequence, LAN/Bluetooth play

First vertical slice: the whole shell plus two games playable end to end,
so every layer is exercised before the other nine games are built on it.

Games
- Euchre: bowers, ordering up, dealer discard, going alone, stick the
  dealer, and full scoring. Rule variants (deck size, points to win,
  stick the dealer, going alone) are toggles in game setup.
- Sequence: two-eyed and one-eyed jacks, free corners, locked sequences,
  the shared-chip limit, and dead-card exchange. Teams, players per team
  and the sequence target are toggles.
- The board layout in SequenceBoard is generated, not the commercial
  board — it holds every structural property the rules need, but does not
  match a physical board. Documented in docs/RULES-sequence.md.

Multiplayer
- One transport abstraction over newline-delimited JSON, implemented
  twice: LAN via NSD discovery and TCP, Bluetooth via Classic RFCOMM.
  A lobby advertises on both at once, so a table can mix them.
- Host-authoritative: clients send move intents, the host re-validates
  every one against the rules, and each client receives a state redacted
  for its own seat so hidden information never crosses the wire.
- Seats start as AI and are handed to people as they join, which is what
  makes any mix of humans and AI work without a separate code path.

Shell
- Main menu lists all eleven games; the nine without engines are marked
  coming soon and are driven entirely by GameCatalog.
- Settings: sound, animation speed (one multiplier drives card movement
  and AI thinking time), and OTA updates from the latest GitHub release.
- Layouts measure available space rather than assuming an orientation.

The game package is free of Android types, so the rules engines and AI
run under plain JUnit; 43 tests cover ranking, following suit, scoring,
sequence detection, redaction, wire round-trips and full random and AI
playthroughs.

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

docs/RULES-euchre.md

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+# Euchre — implemented rules
+
+This is the ruleset the engine enforces, so you can check it against how you
+actually play. Anything marked **toggle** is exposed in the game setup screen;
+anything else is currently fixed and would need a code change.
+
+## Table
+
+- Four players, two fixed partnerships. Seats 0 and 2 are one team, seats 1 and
+  3 are the other, so partners sit opposite each other.
+- The deal rotates one seat clockwise after every hand.
+
+## Deck — *toggle*
+
+- **24 cards** (9, 10, J, Q, K, A in each suit). The standard game.
+- **32 cards** (7 through A). Five cards are still dealt to each player and one
+  is still turned up, so the extra cards simply deepen the undealt remainder.
+  Some 32-card variants deal eight cards and play eight tricks; that is *not*
+  what this does.
+
+## Ranking
+
+With trump named, the order from the top is:
+
+1. **Right bower** — the jack of trump.
+2. **Left bower** — the jack of the *same colour* as trump. It counts as a trump
+   card, not as a card of its printed suit. If spades are trump, the jack of
+   clubs is a spade for the whole hand: it must be played when spades are led,
+   and it does *not* satisfy following clubs.
+3. A, K, Q, 10, 9 of trump.
+
+Non-trump suits rank A, K, Q, J, 10, 9. A card that is neither trump nor of the
+led suit cannot win a trick.
+
+## Bidding
+
+**Round one.** Starting to the dealer's left, each player may order up the
+turned card or pass. Ordering up makes that card's suit trump; the dealer takes
+the card into hand and discards one card face down.
+
+**Round two.** If all four pass, the turn card is turned down and its suit may
+not be named. Starting again to the dealer's left, each player may name any
+other suit or pass.
+
+**Stick the dealer — *toggle*, on by default.** If the first three players pass
+in round two, the dealer must name a suit. With the toggle off, a fourth pass
+throws the hand in and it is redealt by the next dealer.
+
+**Going alone — *toggle*, on by default.** A maker may declare going alone when
+ordering up or naming trump. Their partner sits the hand out entirely and plays
+no cards; the hand is played three-handed.
+
+## Play
+
+- The player to the dealer's left leads to the first trick; after that the
+  winner of each trick leads to the next.
+- You must follow the led suit if you hold it, remembering that the left bower
+  belongs to trump. Otherwise you may play anything.
+- Five tricks are played.
+
+## Scoring
+
+Let the makers be the team that named trump.
+
+| Outcome | Points |
+| --- | --- |
+| Makers take 3 or 4 tricks | 1 to the makers |
+| Makers take all 5 | 2 to the makers |
+| Makers take all 5, playing alone | 4 to the makers |
+| Makers take fewer than 3 (euchred) | 2 to the defenders |
+
+A lone hand that takes 3 or 4 tricks scores 1, the same as an ordinary make.
+
+**Game — *toggle*.** First team to **10** points (default), or 11, or 15.
+
+## Known simplifications
+
+- Cards are dealt five at a time rather than in the traditional 3–2 / 2–3
+  packets. With a shuffled deck this changes nothing about the odds, but it does
+  mean the deal does not *look* like a real one.
+- No defending alone, no farmer's hand, no notrump or misère bids.

docs/RULES-sequence.md

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+# Sequence — implemented rules
+
+This is the ruleset the engine enforces. Anything marked **toggle** is exposed
+in the game setup screen.
+
+## ⚠️ The board layout is not the commercial one
+
+`SequenceBoard.LAYOUT` in `SequenceModel.kt` is a **generated** 10×10 layout, not
+a reproduction of the printed Sequence board. It was generated because the real
+arrangement could not be verified from here, and shipping a guessed one labelled
+as authentic would have been worse than shipping an honest substitute.
+
+It satisfies every property the rules depend on:
+
+- each of the 48 non-jack cards appears exactly twice,
+- the four corners are free squares,
+- no card is adjacent to its own twin (including diagonally).
+
+So the game plays correctly — but square for square it will not match a physical
+board, and two players using this app plus one physical board would disagree.
+To fix that, replace the ten strings in `LAYOUT` with the real arrangement.
+Nothing else needs to change; the parser, the tests and the AI all read from it.
+
+## Table
+
+- **Teams — *toggle*.** Two or three. Seats are dealt round-robin into teams, so
+  team-mates are never seated adjacently.
+- **Players per team — *toggle*.** 1 to 4.
+- **Sequences to win — *toggle*.** Defaults to 2 for two teams and 1 for three
+  teams, matching the usual rule, but can be set explicitly.
+
+## Cards
+
+Two full 52-card decks, shuffled together — 104 cards.
+
+Hand size shrinks as the table grows:
+
+| Players | Cards |
+| --- | --- |
+| 2 | 7 |
+| 3–4 | 6 |
+| 5–6 | 5 |
+| 7–9 | 4 |
+| 10+ | 3 |
+
+After playing a card you draw a replacement. If the draw pile runs out, the
+discards are shuffled to form a new one.
+
+## Turn
+
+Play one card and place a chip on a matching empty square, then draw.
+
+- **Two-eyed jacks** (♦ and ♣) are wild: place a chip on any empty square.
+- **One-eyed jacks** (♥ and ♠) remove one opposing chip — but never a chip that
+  is part of a completed sequence, and never your own team's chip.
+- **Dead card — *toggle*, on by default.** If both squares printed with your card
+  are already occupied, you may discard it and draw a replacement. This does not
+  cost your turn, and you may do it once per turn.
+
+## Sequences
+
+A sequence is five chips in a row — horizontally, vertically or diagonally.
+
+- The **four corners are free squares** and count towards any team's sequence.
+- Two sequences may **share at most one chip**. The engine enforces this by
+  refusing to count a run of five that contains more than one already-locked
+  square.
+- Chips in a completed sequence are locked and cannot be removed by a one-eyed
+  jack.
+
+The first team to reach the sequence target wins immediately.
+
+## Known simplifications
+
+- A completely blocked table (no legal move for anyone) ends the game without a
+  winner rather than triggering a formal draw.
+- The AI does not count cards or track which squares opponents can still reach.