refactor(display): extract dashboard tile grid logic to DisplayManager

libraries/KlubhausCore/src/ScreenState.h

@@ -7,6 +7,31 @@ enum class ScreenID { BOOT, OFF, ALERT, DASHBOARD };
 
 enum class BootStage { SPLASH, INIT_DISPLAY, INIT_NETWORK, CONNECTING_WIFI, READY, DONE };
 
+/// Dashboard tile action handlers
+enum class TileAction {
+    NONE,
+    ALERT,    // Trigger alert
+    SILENCE,  // Silence alert
+    STATUS,   // Send heartbeat/status
+    REBOOT,   // Reboot device
+};
+
+/// Dashboard tile definitions — shared across all boards
+struct DashboardTile {
+    const char* label;
+    uint16_t bgColor; // RGB565
+    TileAction action;
+};
+
+/// Standard dashboard tiles (auto-gridded based on count)
+static constexpr DashboardTile DASHBOARD_TILES[] = {
+    { "Alert",  0x0280, TileAction::ALERT },
+    { "Silent", 0x0400, TileAction::SILENCE },
+    { "Status", 0x0440, TileAction::STATUS },
+    { "Reboot", 0x0100, TileAction::REBOOT },
+};
+static constexpr int DASHBOARD_TILE_COUNT = sizeof(DASHBOARD_TILES) / sizeof(DASHBOARD_TILES[0]);
+
 struct ScreenState {
     DeviceState deviceState = DeviceState::BOOTED;
     ScreenID screen = ScreenID::BOOT;