feat(sprint1-step5): migration Tailwind v4 + Zustand — suppression WildCoinContext

- Install tailwindcss @tailwindcss/vite zustand
- useGameStore.ts : Zustand store wrappant economy.ts (tick, click, buy, prestige, buyNode, loadFromServer)
- GameTick.tsx : composant timer 1s
- GeneratorShop.tsx : boutique générateurs Tailwind (remplace Amelioration.jsx)
- EvolutionTree, PrestigePanel, MilestoneBar : rewrite Zustand + Tailwind
- Hud.jsx : rewrite Zustand + Tailwind (suppression Hud.scss)
- BoutiqueCard, Achievements : migrés vers Zustand
- Supprimé : WildCoin/ (4 fichiers), timer/Timer.jsx, useEconomy.ts, Hud.scss
- WildCoinProvider retiré de main.jsx

Frontend/src/scss/components/Hud.scss

@@ -1,102 +0,0 @@
-.hudContainer {
-  display: flex;
-  flex-direction: column;
-  flex-wrap: wrap;
-  align-items: center;
-  justify-content: space-around;
-
-  min-width: 260px;
-  width: fit-content;
-  max-width: 1280px;
-  height: fit-content;
-
-  gap: 1rem;
-  padding: 1rem;
-  border-radius: 8px;
-  box-sizing: border-box;
-
-  background-color: var(--color-grey);
-  color: var(--color-white);
-
-  font-family: var(--font);
-  color: aliceblue;
-  font-size: 1rem;
-  text-align: center;
-
-  position: absolute;
-  left: 50%;
-  transform: translate(-50%);
-  z-index: 2;
-
-  .hudStats {
-    display: flex;
-    flex-wrap: wrap;
-    gap: 0.8rem;
-
-    .section {
-      display: flex;
-      flex-direction: column;
-      align-items: center;
-      gap: 0.5rem;
-    }
-  }
-
-  .hudBooster {
-    display: flex;
-    flex-wrap: wrap;
-    justify-content: space-around;
-
-    align-items: center;
-    padding: 1rem;
-    gap: 1rem;
-
-    min-width: 280px;
-    width: auto;
-    max-width: 1280px;
-    height: fit-content;
-
-    color: var(--color-white);
-    font-family: var(--font);
-    color: aliceblue;
-    font-size: 1rem;
-    text-align: center;
-
-    border-radius: 8px;
-    box-sizing: border-box;
-
-    .boosterItem {
-      display: flex;
-      flex-wrap: wrap;
-      width: 30px;
-      height: 30px;
-      gap: 0.6rem;
-
-      .boosterIcon {
-        width: 100%;
-        background-size: contain;
-        background-repeat: no-repeat;
-        background-position: center;
-      }
-      .countbox {
-        position: absolute;
-        margin-top: 20px;
-        margin-left: 15px;
-        border: solid 1px var(--color-white);
-        background-color: var(--color-white);
-        border-radius: 20%;
-        padding: 0.1rem;
-        color: var(--color-grey);
-        min-width: 20px;
-        width: fit-content;
-        height: 20px;
-        box-shadow: -1px -1px 7px 0px var(--color-grey);
-      }
-      .boosterCount {
-        font-family: var(--font);
-        font-size: 0.7rem;
-        text-align: center;
-        font-weight: 900;
-      }
-    }
-  }
-}