epub2pdf: title-based export names, .pdf download headers, security hardening (68 tests green)

tests/test_health_index.py

@@ -0,0 +1,18 @@
+"""Liveness + UI entrypoint smoke tests (no conversion involved)."""
+import app
+
+
+def test_health_returns_ok_json(client):
+    resp = client.get("/health")
+    assert resp.status_code == 200
+    body = resp.get_json()
+    assert body["status"] == "ok"
+    assert body["max_upload_mb"] == 400
+
+
+def test_index_serves_ui_html(client):
+    resp = client.get("/")
+    assert resp.status_code == 200
+    text = resp.get_data(as_text=True)
+    assert "<html" in text.lower()
+    assert "/api/convert" in text  # UI knows its upload endpoint