feat(reader): implement FEAT-01 Focus Zen Mode (100% vh/vw, auto-hiding HUD, hotkeys F/Esc, native fullscreen)

tests/test_api.py

@@ -1511,8 +1511,18 @@ def test_grammar_engine_and_handwritten_journaling():
     assert len(u_data["contrasts"]) >= 1
     assert "journaling_prompt" in u_data
     assert "тетрадь" in u_data["journaling_prompt"].lower()
+    assert "cheatsheet_table" in u_data
+    assert "|" in u_data["cheatsheet_table"]
+    assert "detailed_notes" in u_data
+    assert len(u_data["detailed_notes"]) > 100
+    assert "###" in u_data["detailed_notes"]
     assert len(u_data["exercises"]) == 5
 
+    # Check lookup by unit_num directly
+    num_res = client.get("/api/grammar/units/1")
+    assert num_res.status_code == 200
+    assert num_res.json()["id"] == unit_1_id
+
     ex0 = u_data["exercises"][0]
     assert len(ex0["options"]) == 4