feat(frontend): offer the tutorial to newcomers and a practice game

The home page shows newcomers a banner to start the lessons; it goes away for
good after Not now, a lesson or a game. The lessons end with a practice game
against the Easy bot with hints on.

apps/frontend/src/components/PracticeGameCard.tsx

@@ -0,0 +1,47 @@
+import * as React from "react";
+import { FunctionComponent } from "react";
+import { useNavigate } from "react-router-dom";
+import { useTranslation } from "react-i18next";
+import { setHintsEnabled } from "@mancala/core";
+import { Context } from "../context/context";
+import Util from "../util/Util";
+
+// The tutorial's last step: a game against the Easy bot with hints on (R3.1).
+const PracticeGameCard: FunctionComponent<{ context: Context }> = ({ context }) => {
+    const { t } = useTranslation();
+    const navigate = useNavigate();
+    const start = () => {
+        if (Util.checkConnectionAndMaybeAlert(context, t)) return;
+        setHintsEnabled(context.storage, true);
+        navigate("/loby?bot=easy");
+    };
+    return (
+        <section className="practice panel">
+            <div>
+                <strong>{t("PracticeGame")}</strong>
+                <p>{t("PracticeGameText")}</p>
+            </div>
+            <button className="btn pri" onClick={start}>{t("PlayWithBot")}</button>
+            <style jsx>{`
+                .practice {
+                    display: flex;
+                    align-items: center;
+                    justify-content: space-between;
+                    flex-wrap: wrap;
+                    gap: 12px;
+                    padding: 18px 22px;
+                    flex-shrink: 0;
+                }
+                strong {
+                    font-size: 18px;
+                }
+                p {
+                    margin: 4px 0 0;
+                    color: var(--muted);
+                }
+            `}</style>
+        </section>
+    );
+};
+
+export default PracticeGameCard;

apps/frontend/src/components/home/TutorialBanner.tsx

@@ -0,0 +1,47 @@
+import * as React from "react";
+import { FunctionComponent, useState } from "react";
+import { useNavigate } from "react-router-dom";
+import { useTranslation } from "react-i18next";
+import { hideTutorialBanner, shouldShowTutorialBanner } from "@mancala/core";
+import { Context } from "../../context/context";
+
+// For newcomers: an offer to learn the game, until they open the lessons, play a game or say not now (R4).
+const TutorialBanner: FunctionComponent<{ context: Context }> = ({ context }) => {
+    const { t } = useTranslation();
+    const navigate = useNavigate();
+    const [visible, setVisible] = useState(() => shouldShowTutorialBanner(context.storage));
+    if (!visible) return null;
+    return (
+        <section className="tbanner panel">
+            <strong>{t("NewToMangala")}</strong>
+            <div className="actions">
+                <button className="btn pri" onClick={() => navigate("/learn")}>{t("StartTutorial")}</button>
+                <button className="btn ghost" onClick={() => {
+                    hideTutorialBanner(context.storage);
+                    setVisible(false);
+                }}>{t("NotNow")}</button>
+            </div>
+            <style jsx>{`
+                .tbanner {
+                    display: flex;
+                    align-items: center;
+                    justify-content: space-between;
+                    flex-wrap: wrap;
+                    gap: 12px;
+                    padding: 18px 22px;
+                    flex-shrink: 0;
+                    box-shadow: inset 0 0 0 2px var(--accent);
+                }
+                strong {
+                    font-size: 18px;
+                }
+                .actions {
+                    display: flex;
+                    gap: 10px;
+                }
+            `}</style>
+        </section>
+    );
+};
+
+export default TutorialBanner;

apps/frontend/src/routes/Home.tsx

@@ -7,6 +7,7 @@ import PageContainer from "../components/PageContainer";
 import { PlusIcon } from "../components/Icons";
 import BotLevelMenu from "../components/BotLevelMenu";
 import ActiveGameBanner from "../components/home/ActiveGameBanner";
+import TutorialBanner from "../components/home/TutorialBanner";
 import LiveGamesSection from "../components/home/LiveGamesSection";
 import RecentGamesSection from "../components/home/RecentGamesSection";
 import PopularGamesSection from "../components/home/PopularGamesSection";
@@ -58,6 +59,7 @@ const Home: FunctionComponent<{
         </button>
       </AppHeader>
       <main className="wrap">
+        <TutorialBanner context={context} />
         {activeGame && authUser && (
           <ActiveGameBanner
             game={activeGame}

apps/frontend/src/routes/LearnPage.tsx

@@ -6,6 +6,7 @@ import { getCompletedLessons, hideTutorialBanner, LESSON_RULES, Theme } from "@m
 import AppHeader from "../components/headerbar/AppHeader";
 import PageContainer from "../components/PageContainer";
 import { Context } from "../context/context";
+import PracticeGameCard from "../components/PracticeGameCard";
 
 // The lessons in order, the ones done marked (docs/specs/tutorial, R2.6).
 const LearnPage: FunctionComponent<{ context: Context, theme: Theme }> = ({ context }) => {
@@ -31,6 +32,7 @@ const LearnPage: FunctionComponent<{ context: Context, theme: Theme }> = ({ cont
                         );
                     })}
                 </ol>
+                <PracticeGameCard context={context} />
                 <Link className="rules-link" to="/rules">{t("HowToPlay")}</Link>
             </main>
             <style jsx>{`

apps/frontend/src/routes/LessonPage.tsx

@@ -12,6 +12,7 @@ import AppHeader from "../components/headerbar/AppHeader";
 import PageContainer from "../components/PageContainer";
 import BoardView from "../components/board/BoardView";
 import { Context } from "../context/context";
+import PracticeGameCard from "../components/PracticeGameCard";
 
 const YOU = "you";
 const OPPONENT = "opponent";
@@ -130,6 +131,7 @@ const LessonPage: FunctionComponent<{ context: Context, theme: Theme }> = ({ con
                         </>
                     )}
                 </div>
+                {fulfilled && !next && <PracticeGameCard context={context} />}
                 {game && boardViewModel && (
                     <div className="lboard">
                         <BoardView

apps/frontend/src/routes/LobyPage.tsx

@@ -5,6 +5,7 @@ import { useNavigate, useSearchParams } from 'react-router-dom';
 import AppHeader from '../components/headerbar/AppHeader';
 import PageContainer from '../components/PageContainer';
 import { BOT_OFFER_DELAY_MS, BotLevel, channel_cancel_new_game, channel_new_bot_game, channel_new_game, channel_on_game_start, channel_on_new_game_rejected, isBotLevel } from '@mancala/core';
+import { markGamePlayed } from '@mancala/core';
 import BotLevelPicker from '../components/BotLevelPicker';
 import { Context } from '../context/context';
 import { Theme } from '@mancala/core';
@@ -35,6 +36,7 @@ const LobyPage: FunctionComponent<{
 
     const onGameStart = (message: Object) => {
         const newGame: CommonMancalaGame = message as CommonMancalaGame;
+        markGamePlayed(context.storage);
         navigate(`/game/${newGame.id}`)
     }
 

docs/specs/tutorial/tasks.md

@@ -9,7 +9,7 @@ Work through the tasks in order; each ends with its tests passing and a commit.
       game page.
 - [x] 4. **Lessons**: `/learn` with progress, `LessonPage` with the local game, animation, praise, explanation and
       reset, scripted opponent replies.
-- [ ] 5. **Newcomers and practice game**: `TutorialBanner`, `markGamePlayed`, the practice game button.
+- [x] 5. **Newcomers and practice game**: `TutorialBanner`, `markGamePlayed`, the practice game button.
 - [ ] 6. **Hints**: hint chips on `BoardView`, the explanation line and the "Hints" switch in bot games on `GamePage`.
 - [ ] 7. **Mobile rules**: `RulesScreen`, links from the help and game screens; type check and bundle.
 - [ ] 8. **End to end and docs**: the Chrome tests from `design.md`; `AGENTS.md` (specs list), `TODO.md` (out of scope