Add a web UI to the clock firmware

- Web UI on port 80: live view of the display, choose the page (clock or
  a bitmap), bitmaps (list, show, live, edit, delete), draw / image upload
  with conversion in the browser, live mode, settings, Home Assistant
- Live view from a shadow buffer in the BROSE9323 driver (shownPixel)
- Settings in NVS with the original behaviour as defaults: schedule times,
  quarter hours, yawning Pikachu, No WiFi screen, flip time, status LED,
  Home Assistant broker (restart on change)
- Bitmaps on LittleFS; new 320 KB partition, ota slots now 1.31 MB
- DisplayController: pages, live mode, settings; app.cpp holds the objects
- README for the recovery app; docs for the web UI
- Tests: settings, time parsing, bitmap format and names, schedule with
  settings, pages and live mode (95 total)

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

src/esp32/display/frames.h

@@ -1,6 +1,7 @@
 #pragma once
 
 #include "BROSE9323.h"
+#include "logic/bitmap_format.h"
 #include "logic/display_controller.h"
 
 // Draws the screens on the flipdot display. Each method sends one complete frame.
@@ -10,13 +11,24 @@ public:
 	explicit FlipdotFrames(BROSE9323 &display);
 
 	// Pikachu with a thought bubble showing HH:MM (yawning in the evening)
-	void clock(int hour, int minute) override;
+	void clock(int hour, int minute, bool evening) override;
 	// "No WiFi" with the time below it
 	void noWifi(int hour, int minute) override;
+	// The bitmap set with setPageBitmap()
+	void page() override;
+	// The image set with setLiveBitmap()
+	void live() override;
 	// Nintendo logo
 	void logo() override;
 	void blank() override;
 
+	void setPageBitmap(const uint8_t *bitmap);
+	void setLiveBitmap(const uint8_t *bitmap);
+
 private:
 	BROSE9323 &_display;
+	uint8_t _page[BITMAP_BYTES] = {};
+	uint8_t _live[BITMAP_BYTES] = {};
+
+	void _drawFullScreen(const uint8_t *bitmap);
 };