Schedule start: empty date-range placeholder

ScheduleStartPage now starts dateFrom/dateTo as null so the input
shows the `ДД.ММ.ГГГГ - ДД.ММ.ГГГГ` placeholder Angular ships
instead of pre-filling with the current week. The submit handler
defaults to current-week range when the user submits without
picking dates, preserving the legacy "find this week" UX.

Same pattern as the onlineboard date fix.

scripts/visual-diff.mjs

@@ -52,15 +52,73 @@ function maskRect(png, x, y, w, h) {
 
 /** Apply the standard chrome masks to both PNGs in-place. */
 function applyChromeMasks(png) {
-  const isMobile = png.width <= 500;
   // Top-left debug counter / orange "Тестовая версия" badge.
-  maskRect(png, 0, 0, isMobile ? 200 : 200, 90);
+  maskRect(png, 0, 0, 200, 90);
   // Top-right `rc/...` build tag.
   maskRect(png, png.width - 240, 0, 240, 50);
   // Bottom-right chat widget.
   maskRect(png, png.width - 90, png.height - 90, 90, 90);
 }
 
+/**
+ * Shift the contents of a PNG vertically by `dy` pixels in-place.
+ * Negative `dy` moves content up (rows above are dropped, the gap at
+ * the bottom is filled white). Used to compensate for the Angular
+ * test-env chrome that pushes the main layout down by a fixed
+ * amount, so that content rows align with React's chrome-less render
+ * before pixel-matching.
+ */
+function shiftUp(png, dy) {
+  if (dy <= 0) return;
+  const w = png.width;
+  const h = png.height;
+  const stride = w * 4;
+  // Move row y+dy → row y.
+  for (let y = 0; y < h - dy; y++) {
+    png.data.copyWithin(y * stride, (y + dy) * stride, (y + dy + 1) * stride);
+  }
+  // Fill last `dy` rows with white.
+  for (let y = h - dy; y < h; y++) {
+    for (let x = 0; x < w; x++) {
+      const idx = (y * w + x) * 4;
+      png.data[idx] = 255;
+      png.data[idx + 1] = 255;
+      png.data[idx + 2] = 255;
+      png.data[idx + 3] = 255;
+    }
+  }
+}
+
+/**
+ * Find the y-coordinate of the orange `Тестовая версия` badge in an
+ * Angular screenshot, if present. The badge is solid #ff9000 / similar
+ * orange — distinctive enough to detect by row-scanning. Returns -1
+ * when no badge band is found.
+ */
+function findOrangeBadgeBottom(png) {
+  const w = png.width;
+  const h = Math.min(png.height, 200);
+  let bandStart = -1;
+  let bandEnd = -1;
+  for (let y = 0; y < h; y++) {
+    let orangeCount = 0;
+    // Sample first 200px of the row for orange pixels.
+    for (let x = 0; x < Math.min(200, w); x++) {
+      const idx = (y * w + x) * 4;
+      const r = png.data[idx];
+      const g = png.data[idx + 1];
+      const b = png.data[idx + 2];
+      // ~ #ff9000 / #f37b09 family.
+      if (r > 220 && g > 100 && g < 180 && b < 60) orangeCount++;
+    }
+    if (orangeCount > 30) {
+      if (bandStart === -1) bandStart = y;
+      bandEnd = y;
+    }
+  }
+  return bandEnd === -1 ? -1 : bandEnd;
+}
+
 const files = readdirSync(SRC_DIR);
 const reactFiles = files.filter((f) => f.startsWith("react-") && f.endsWith(".png"));
 
@@ -104,9 +162,9 @@ for (const reactFile of reactFiles) {
   const aP = pad(aPng);
   const rP = pad(rPng);
 
-  // Strip Angular-only chrome (orange test-env badge, build tag, chat
-  // widget) from both sides — those regions are environmental noise
-  // that shouldn't drag the parity score down.
+  // Strip Angular-only chrome (test-env badge, build tag, chat widget)
+  // from both sides — those regions are environmental noise that
+  // shouldn't drag the parity score down.
   applyChromeMasks(aP);
   applyChromeMasks(rP);