feat: complete Phase 1 - game library, lifecycle, realtime sync

- Seed 33 popular games across 5 platforms via admin API script
- Add GameDetailDialog with game info and quick-team button
- Update GamesLibrary with game card click to open detail dialog
- Update Home hot games to open detail dialog instead of navigating
- Rewrite invitation accept: frontend auto-joins team + updates status
- Add user status reset on team dissolution (endGame)
- Add start game / dissolve buttons to TeamSessionPanel lifecycle
- Integrate realtime subscriptions in GroupView and Layout
- Add notification store realtime invitation listener
- Add placeholder images for game covers and avatars
- Remove Go hooks, add JS hooks placeholder + Docker mount

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

frontend/src/components/team/TeamSessionPanel.vue

@@ -19,6 +19,14 @@ const memberDetails = computed(() => {
     .filter((m): m is NonNullable<typeof m> => Boolean(m))
 })
 
+async function startGame() {
+  try {
+    await teamStore.updateStatus('playing')
+  } catch {
+    // ignore
+  }
+}
+
 async function endGame() {
   try {
     await ElMessageBox.confirm(
@@ -67,9 +75,15 @@ async function endGame() {
       </div>
     </div>
 
-    <button class="end-game-btn" @click="endGame">
+    <button v-if="session.status === 'recruiting'" class="start-game-btn" @click="startGame">
+      开始游戏
+    </button>
+    <button v-else-if="session.status === 'playing'" class="end-game-btn" @click="endGame">
       游戏结束
     </button>
+    <button v-if="session.status === 'recruiting'" class="dissolve-btn" @click="endGame">
+      解散小组
+    </button>
   </div>
 
   <div v-else class="no-session">
@@ -177,6 +191,43 @@ async function endGame() {
   color: var(--gg-text);
 }
 
+.start-game-btn {
+  width: 100%;
+  padding: 12px;
+  margin-bottom: 8px;
+  border: none;
+  border-radius: var(--gg-radius-sm);
+  background: var(--gg-gradient-green);
+  color: white;
+  font-size: 14px;
+  font-weight: 600;
+  cursor: pointer;
+  transition: opacity 0.2s, box-shadow 0.2s;
+}
+
+.start-game-btn:hover {
+  opacity: 0.9;
+  box-shadow: 0 4px 16px rgba(5, 150, 105, 0.3);
+}
+
+.dissolve-btn {
+  width: 100%;
+  padding: 10px;
+  border: 1px solid var(--gg-border);
+  border-radius: var(--gg-radius-sm);
+  background: transparent;
+  color: var(--gg-text-secondary);
+  font-size: 13px;
+  font-weight: 500;
+  cursor: pointer;
+  transition: all 0.2s;
+}
+
+.dissolve-btn:hover {
+  border-color: var(--gg-danger);
+  color: var(--gg-danger);
+}
+
 .end-game-btn {
   width: 100%;
   padding: 12px;