Home Assistant requests in a task, progress bar, Plex page, bitmap cache

- net/ha_api: the HTTP requests run in a FreeRTOS task on core 0; loop()
  only hands over copies through queues. The web UI's test button polls.
  No more 3-4 s loop() stalls once a minute; timeout raised to 5 s.
- Progress bar page element (page format 4, v3 pages are converted)
- Plex user setting (settings v6): {plex_user} in entity ids
- Plex page (examples): watchers, play/pause icon, title, progress
- Bitmaps cached in RAM: a LittleFS read took ~100 ms on every render
  and web preview; long JSON lists sent in 2 KB pieces
- Backup includes the refresh settings and the Plex user

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

src/esp32/logic/page_render.cpp

@@ -89,6 +89,38 @@ static void drawImage(const PageElement &e, PageResources &resources, uint8_t *b
 			}
 }
 
+// Bar: a frame (optional) filled from the left by the Home Assistant value
+static void drawBar(const PageElement &e, PageResources &resources, uint8_t *bitmap, ElementBox &box)
+{
+	int w = e.bar_width, h = e.bar_height;
+	int left = e.x;
+	if (e.align == Align::Center)
+		left -= w / 2;
+	else if (e.align == Align::Right)
+		left -= w;
+	box.x = left;
+	box.y = e.y;
+	box.width = w;
+	box.height = h;
+	if (e.overlay == Overlay::Box)
+		clearBox(bitmap, left - 1, e.y - 1, w + 2, h + 2);
+
+	// With a frame the fill is inside it (a bar of 1 or 2 dots high has no room: no frame)
+	bool frame = e.bar_frame && w >= 3 && h >= 3;
+	int inner = frame ? 1 : 0;
+	int fill = barFill(e, resources.haValue(e), w - 2 * inner);
+	for (int y = 0; y < h; y++)
+		for (int x = 0; x < w; x++)
+		{
+			bool edge = frame && (x == 0 || y == 0 || x == w - 1 || y == h - 1);
+			bool filled = !edge && x - inner < fill;
+			if (!edge && !filled)
+				continue;
+			int bx = left + x, by = e.y + y;
+			setBitmapPixel(bitmap, bx, by, e.overlay == Overlay::Invert ? !bitmapPixel(bitmap, bx, by) : true);
+		}
+}
+
 // A text element; returns the ms until it scrolls on (0: it doesn't scroll)
 static uint32_t drawTextElement(const PageElement &e, const char *text, uint32_t now_ms, PageResources &resources,
 								uint8_t *bitmap, ElementBox &box)
@@ -152,6 +184,8 @@ uint32_t renderPage(const DynamicPage &page, const LocalTime &time, uint32_t now
 		ElementBox box;
 		if (e.type == ElementType::Image)
 			drawImage(e, resources, bitmap, box);
+		else if (e.type == ElementType::Bar)
+			drawBar(e, resources, bitmap, box);
 		else
 		{
 			ElementValues values;