Schedule pages and rotation rules can be skipped in slow mode

Each page in a schedule block, and each rule that adds its page to the
rotation, has a "skip in slow mode" checkbox. While slow mode is on those
pages are left out of the rotation; when none of the block's pages are
left, the chosen page is shown. The rotation keeps its own timers.

Schedule format version 5; version 4 is converted when read and stored
again in version 5 on the next save.

Version 2.18.0.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/esp32/config.h

@@ -118,7 +118,7 @@ const uint32_t SETUP_AP_DELAY = 20000;        // open the AP when WiFi fails thi
 const uint32_t WIFI_CONNECT_TIMEOUT = 30000;
 const uint32_t WIFI_RESTART_TIME = 10UL * 60 * 1000;
 
-#define FIRMWARE_VERSION "2.17.0"
+#define FIRMWARE_VERSION "2.18.0"
 
 // Home Assistant device id (do not change: Home Assistant's entities are linked to it)
 const uint8_t HA_DEVICE_ID[] = {0x34, 0x86, 0x5d, 0x3a, 0x08, 0x28};