feat: dashboard manifest supports 'supported_games' field, frontend filters by selected game

- DashboardTheme model adds supported_games (default: 'all')
- Built-in dashboards declare game compatibility:
  speedometer/tachometer/gear_indicator -> all
  lap_timer -> forza_horizon_5,forza_horizon_4,forza_motorsport,f1_24
- Dashboard browser filters themes by selected game
- Card shows '全' (all) or '限' (limited) badge
- Updated DASHBOARD_DEV.md with supported_games spec

models/dashboard.py

@@ -30,6 +30,7 @@ class DashboardTheme:
     icon: str = "📊"
     aspect_ratio: str = "auto"
     render_mode: str = "contain"
+    supported_games: str = "all"
     created_at: str = ""
     updated_at: str = ""
     is_builtin: bool = False
@@ -46,6 +47,7 @@ class DashboardTheme:
             "icon": self.icon,
             "aspect_ratio": self.aspect_ratio,
             "render_mode": self.render_mode,
+            "supported_games": self.supported_games,
             "created_at": self.created_at,
             "updated_at": self.updated_at,
             "is_builtin": self.is_builtin,
@@ -67,6 +69,7 @@ class DashboardTheme:
                 icon=config.get("icon", "📊"),
                 aspect_ratio=config.get("aspect_ratio", "auto"),
                 render_mode=config.get("render_mode", "contain"),
+                supported_games=data.get("supported_games", "all"),
                 created_at=data.get("created_at", ""),
                 updated_at=data.get("updated_at", ""),
                 is_builtin=is_builtin,
@@ -137,6 +140,7 @@ class DashboardManager:
             "description": theme.description,
             "author": theme.author,
             "version": theme.version,
+            "supported_games": theme.supported_games,
             "config": {
                 "icon": theme.icon,
                 "aspect_ratio": theme.aspect_ratio,