Add Sycamore/WASM frontend and restructure into server/ + web/

Repo is now a monorepo:

- server/: the kaya backend, unchanged in behaviour, plus:
  - GET /api/me for SPA session detection
  - last_move recorded on every play and broadcast in the game state, so
    clients can show who played which card the moment they play it
  - legal_moves per hand card for the player on turn (rules stay
    server-side)
  - static catch-all route serving the compiled SPA with index.html
    fallback; Tortoise context now bound only for /api/* requests
  - configurable OIDC post-login/logout redirects for dev against trunk
- web/: Sycamore 0.9 + WASM frontend (trunk): login via the OIDC flow,
  lobby (create match / join by code), live game page over websocket with
  card images (CC0 woodcut napoletane deck), capture picker, move banner,
  game-over overlay, match history and leaderboard pages
- server/Dockerfile gains a rust+trunk stage building web/dist; the single
  app image serves the SPA; compose builds from the repo root with
  overridable ports/OIDC env

Verified end-to-end against the compose stack: four OIDC logins, game
creation, three joins by code, websocket play with broadcasts to all
players and out-of-turn rejection. 51 backend tests, mypy and cargo tests
all green.

server/pyproject.toml

@@ -0,0 +1,61 @@
+[build-system]
+requires = ["setuptools>=68"]
+build-backend = "setuptools.build_meta"
+
+[project]
+name = "scopa"
+version = "0.1.0"
+description = "Scopone scientifico multiplayer backend built on the kaya framework"
+readme = "README.md"
+requires-python = ">=3.10"
+dependencies = [
+    "kaya-core",
+    "kaya-session",
+    "kaya-session-redis",
+    "kaya-oidc",
+    "kaya-openapi",
+    "kaya-rsgi",
+    "granian>=2.0",
+    "tortoise-orm",
+    "aerich",
+    "asyncpg",
+    "httpx",
+    "PyJWT[crypto]",
+    "pwo",
+    "redis",
+]
+
+[project.optional-dependencies]
+dev = [
+    "mypy",
+    "httpx-ws",
+]
+
+[tool.setuptools.packages.find]
+where = ["src"]
+namespaces = false
+
+# Database migrations (aerich). See the Migrations section in README.md.
+[tool.aerich]
+tortoise_orm = "scopa.aerich_config.TORTOISE_ORM"
+location = "./migrations"
+
+[tool.mypy]
+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 = "scopa.models"
+disable_error_code = ["attr-defined"]
+
+[[tool.mypy.overrides]]
+module = "scopa.routes.*"
+disable_error_code = ["attr-defined"]
+
+[[tool.mypy.overrides]]
+module = "scopa.game.*"
+disable_error_code = ["attr-defined"]