Measure AppContainer disk quota overshoot

SovereignAI-Starter/scripts/appcontainer_disk_fill_smoke.py

@@ -0,0 +1,14 @@
+"""Fills only the disposable AppContainer profile to verify the broker quota."""
+
+import os
+from pathlib import Path
+
+target = Path(__file__).with_name("disk-fill.bin")
+chunk = b"x" * (64 * 1024)
+with target.open("wb") as output:
+    while True:
+        output.write(chunk)
+        output.flush()
+        # Force the disposable test writes through the file cache so the
+        # broker's disk monitor observes durable growth, not buffered writes.
+        os.fsync(output.fileno())