Improve render lifecycle, geometry, and PDF parity

render-repros/representative-suite/run.sh

@@ -13,6 +13,7 @@ usage() {
   echo "SCROLL_Y is an integer CSS-pixel offset or 'bottom'." >&2
   echo "Set CAPTURE_MODE=live to leave animations and runtime state unfrozen." >&2
   echo "CAPTURE_MODE defaults to deterministic (Chromium animations sampled at T=0)." >&2
+  echo "Set SETTLE_MS=0 for latency runs; visual runs default to 3000." >&2
 }
 
 if [[ "${1:-}" == "--help" || "${1:-}" == "-h" ]]; then
@@ -26,10 +27,15 @@ fi
 
 OUT="$1"
 CAPTURE_MODE="${CAPTURE_MODE:-deterministic}"
+SETTLE_MS="${SETTLE_MS:-3000}"
 if [[ "$CAPTURE_MODE" != "deterministic" && "$CAPTURE_MODE" != "live" ]]; then
   echo "CAPTURE_MODE must be 'deterministic' or 'live': $CAPTURE_MODE" >&2
   exit 2
 fi
+if [[ ! "$SETTLE_MS" =~ ^[0-9]+$ ]] || (( SETTLE_MS % 1000 != 0 )); then
+  echo "SETTLE_MS must be a non-negative whole number of seconds in milliseconds: $SETTLE_MS" >&2
+  exit 2
+fi
 if [[ -e "$OUT" ]]; then
   echo "output path already exists: $OUT" >&2
   exit 2
@@ -46,7 +52,7 @@ args=(
   --out "$OUT"
   --width 1440
   --height 1000
-  --settle-ms 3000
+  --settle-ms "$SETTLE_MS"
   --geometry-selector "header, nav, footer"
   --geometry-selector "main, article"
   --geometry-selector "section"

render-repros/representative-suite/test_suite.py

@@ -129,6 +129,22 @@ class RepresentativeSuiteTests(unittest.TestCase):
         self.assertEqual(result.returncode, 0, result.stderr)
         self.assertNotIn("--animation-time-ms", arguments)
 
+    def test_zero_settle_latency_mode_is_forwarded(self):
+        result, arguments, _, _ = self.run_wrapper(
+            extra_environment={"SETTLE_MS": "0"},
+        )
+        self.assertEqual(result.returncode, 0, result.stderr)
+        settle_index = arguments.index("--settle-ms")
+        self.assertEqual(arguments[settle_index + 1], "0")
+
+    def test_fractional_settle_is_rejected_before_capture(self):
+        result, arguments, _, _ = self.run_wrapper(
+            extra_environment={"SETTLE_MS": "1500"},
+        )
+        self.assertEqual(result.returncode, 2)
+        self.assertEqual(arguments, [])
+        self.assertIn("SETTLE_MS must be", result.stderr)
+
     def test_invalid_capture_mode_is_rejected_before_capture(self):
         result, arguments, _, _ = self.run_wrapper(
             extra_environment={"CAPTURE_MODE": "almost-live"},