diff --git a/entrypoint.sh b/entrypoint.sh
index bfd4d792..a11fbc96 100644
--- a/entrypoint.sh
+++ b/entrypoint.sh
@@ -235,7 +235,11 @@ test_write() {
         return 1
     fi
 
-    if ! run_as_target_user sh -c 'echo 0123456789_TEST > "$1"' _ "$test_file"; then
+    # This is a probe: a failure here is expected (e.g. a fresh root-owned bind
+    # mount) and is recovered by the caller via change_ownership + re-probe. Hide
+    # the shell's "Permission denied"/"Read-only file system" stderr so a handled
+    # probe miss doesn't masquerade as a real boot failure in the logs.
+    if ! run_as_target_user sh -c 'echo 0123456789_TEST 2>/dev/null > "$1"' _ "$test_file"; then
         echo "Failed to write test file in $folder as $USERNAME"
         return 1
     fi
@@ -448,6 +452,12 @@ else
     if [ $config_ok -ne 0 ]; then
         fail_unwritable_config_dir "$CONFIG_PATH"
     fi
+
+    # The ingest/destination library (default /books) is user data and may be a
+    # bind mount owned by another uid; downloads fail with "Destination not
+    # writable" if the runtime user can't write there. Fix the top-level dir only
+    # (root mode) so we don't recursively chown a potentially huge library.
+    make_writable "${INGEST_DIR:-/books}" root
 fi
 
 # Always run Gunicorn (even when DEBUG=true) to ensure Socket.IO WebSocket
diff --git a/tests/e2e/platform/suite/conftest.py b/tests/e2e/platform/suite/conftest.py
index e672fe3a..864100cc 100644
--- a/tests/e2e/platform/suite/conftest.py
+++ b/tests/e2e/platform/suite/conftest.py
@@ -17,10 +17,16 @@ from __future__ import annotations
 import os
 import time
 from dataclasses import dataclass, field
+from pathlib import Path
 
 import pytest
 import requests
 
+# This conftest's pytest_collection_modifyitems hook receives the *whole*
+# session's items (not just ones under this dir), so scope our marking to the
+# suite to avoid tagging the entire repo's tests as platform/e2e.
+_SUITE_DIR = Path(__file__).resolve().parent
+
 BASE_URL = os.environ.get("E2E_BASE_URL", "http://localhost:8084")
 ACTIVE_PROFILE = os.environ.get("E2E_PROFILE", "baseline")
 DEFAULT_TIMEOUT = 15
@@ -124,7 +130,10 @@ def pytest_collection_modifyitems(config: pytest.Config, items: list[pytest.Item
     everywhere (this is the matrix: invariants x profiles).
     """
     for item in items:
+        if not item.path.is_relative_to(_SUITE_DIR):
+            continue
         item.add_marker(pytest.mark.platform)
+        item.add_marker(pytest.mark.e2e)
         marker = item.get_closest_marker("profiles")
         if marker and ACTIVE_PROFILE not in marker.args:
             item.add_marker(