Split backend into tavolo-platform, tavolo-scopone and tavolo-app packages

Move the game-independent machinery (lobby, live-game store, websocket,
deadline scheduler, match history, leaderboards) into a new
tavolo-platform distribution behind a GameEngine contract, the scopone
scientifico rules plus a platform adapter into tavolo-scopone, and keep
only the composition root in tavolo-app. The three distributions share
the tavolo namespace (PEP 420, kaya-style monorepo).

Match history becomes fully generic: Match carries the engine's result
JSON and MatchPlayer points/details instead of scopone-shaped team
columns (migration 3 backfills existing rows). Lobby creation takes an
opaque per-game options object and websocket actions dispatch to the
session's engine.

Tests: platform suite runs against a DummyEngine toy game, scopone
keeps the rules tests plus new adapter tests, server/tests covers the
wired stack end to end (194 tests, was 143).

server/pyproject.toml

@@ -3,12 +3,14 @@ requires = ["setuptools>=68"]
 build-backend = "setuptools.build_meta"
 
 [project]
-name = "tavolo"
+name = "tavolo-app"
 version = "0.1.0"
-description = "Multiplayer card-game platform backend built on the kaya framework"
+description = "Tavolo multiplayer card-game application: platform + scopone game wiring"
 readme = "README.md"
 requires-python = ">=3.10"
 dependencies = [
+    "tavolo-platform",
+    "tavolo-scopone",
     "kaya-core",
     "kaya-cors",
     "kaya-session",
@@ -17,9 +19,8 @@ dependencies = [
     "kaya-openapi",
     "kaya-rsgi",
     "granian>=2.0",
-    "tortoise-orm",
-    "aerich",
     "asyncpg",
+    "aerich",
     "httpx",
     "PyJWT[crypto]",
     "pwo",
@@ -38,7 +39,7 @@ otel = [
 
 [tool.setuptools.packages.find]
 where = ["src"]
-namespaces = false
+namespaces = true
 
 # Database migrations (aerich). See the Migrations section in README.md.
 [tool.aerich]
@@ -49,18 +50,3 @@ location = "./migrations"
 python_version = "3.12"
 ignore_missing_imports = true
 plugins = []
-
-# TortoiseORM auto-generates `<fk>_id` attributes on ForeignKeyField at
-# runtime; without the (unavailable here) tortoise mypy plugin the stubs
-# only declare the relation field. These are real attributes, not bugs.
-[[tool.mypy.overrides]]
-module = "tavolo.models"
-disable_error_code = ["attr-defined"]
-
-[[tool.mypy.overrides]]
-module = "tavolo.routes.*"
-disable_error_code = ["attr-defined"]
-
-[[tool.mypy.overrides]]
-module = "tavolo.game.*"
-disable_error_code = ["attr-defined"]