Add HA dropdowns, off image, flip fixes and refresh effects

Home Assistant: remove the Clock switch (its entity is deleted on connect),
add an IP sensor and Mode / Off image dropdowns whose options follow the
saved bitmaps. Remove the built-in "Nintendo border" bitmap.

Off image: a bitmap (or blank) left on the dots when the display switches off.

Nano: pause after each flip pulse and repeat pulses for changed dots, both
stored in EEPROM (G/N commands). Refresh effects (E command): instant,
sparkle, wipe, rain, from the middle out, diagonal, spiral, flip all then
reveal, push and random, optionally only for small changes. Effects run in
steps from loop() so serial input keeps flowing.

Web UI: flip settings, refresh effect and test patterns under Settings; the
System tab shows why the ESP32 last restarted. Settings records from
versions 1 and 2 are migrated. Firmware 2.3.0.

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

src/esp32/display/frames.h

@@ -18,17 +18,19 @@ public:
 	void page() override;
 	// The image set with setLiveBitmap()
 	void live() override;
-	// Nintendo logo
-	void logo() override;
-	void blank() override;
+	// Blank, or the bitmap set with setOffBitmap()
+	void off() override;
 
 	void setPageBitmap(const uint8_t *bitmap);
 	void setLiveBitmap(const uint8_t *bitmap);
+	// nullptr: blank
+	void setOffBitmap(const uint8_t *bitmap);
 
 private:
 	BROSE9323 &_display;
 	uint8_t _page[BITMAP_BYTES] = {};
 	uint8_t _live[BITMAP_BYTES] = {};
+	uint8_t _off[BITMAP_BYTES] = {}; // all zero: blank
 
 	void _drawFullScreen(const uint8_t *bitmap);
 };