feat: remove a saved game & redirect on missing/deleted game (#20)

- DELETE /api/games/:id route + Db.delete() (404 when absent)
- PresetPicker: per-saved-game trash button + confirm dialog (Cancel/Delete)
- App: runDeleteGame; useSse onError -> goHome on 'deleted'/'not found'
  (a deleted/missing game now returns the live tab and any deep link home)
- DeleteGameResponse in shared/protocol.ts; api.deleteGame()
- unit test (Db.delete) + 2 e2e tests (home-screen delete; in-flight delete
  returns the active tab home and a fresh deep link lands on home)
- version 0.7.0 -> 0.8.0 + changelog

Fixes #20

src/App.tsx

@@ -309,6 +309,12 @@ export default function App() {
   useSse(game?.id ?? null, {
     onState: applyState,
     onTurn: applyState,
+    // The game disappeared while this tab had it open — either deleted from
+    // another tab (the server broadcasts an SSE `error`) or a stale deep link to
+    // a missing game (the SSE connect emits `error`). Return this tab home.
+    onError: (msg) => {
+      if (/deleted|not found/i.test(msg)) latestRef.current?.goHome();
+    },
   });
 
   const play = useCallback(async (presetId: string) => {
@@ -465,6 +471,29 @@ export default function App() {
     setAdvisors([]);
   }, []);
 
+  // Delete a saved game. Removes it from the "Saved games" list, clears it if it
+  // was the remembered active game, and heads home if it's the one currently
+  // shown. The server also broadcasts an SSE `error` to any *other* open tab of
+  // this game, which the `useSse` `onError` handler above turns into a go-home.
+  const runDeleteGame = useCallback(
+    async (id: string) => {
+      try {
+        await api.deleteGame(id);
+      } catch (e) {
+        toastError(e);
+        return;
+      }
+      setSavedGames((prev) => prev.filter((g) => g.id !== id));
+      if (activeGameId === id) {
+        clearActiveGameId();
+        setActiveGameId(null);
+      }
+      if (game?.id === id) goHome();
+      toast.success('Game deleted');
+    },
+    [activeGameId, game, goHome],
+  );
+
   // Expose the latest game + handlers to the mount-once hashchange listener.
   latestRef.current = { game, goHome, loadGame };
 
@@ -509,6 +538,7 @@ export default function App() {
         savedGames={savedGames}
         activeGameId={activeGameId}
         onResume={resumeGame}
+        onDelete={runDeleteGame}
       />
     </>
   );