Add pump profile fetching and Insulineprofiel page

Fetch and parse the latest-used Nightscout profile (basal schedule, ISF,
carb ratio, DIA, targets) and show it as a new dashboard page: a list of
basal/ISF/carb-ratio segments plus a bar chart of basal rate by hour of
day. This is the data foundation for treatment overlays on the glucose
charts and the redesigned PDF report in follow-up PRs.

tests/test_nightscout_client.py

@@ -357,6 +357,29 @@ def test_fetch_treatments_range_retrieves_full_history_even_with_a_hidden_server
     assert result["timestamp"].max().date() == end_date
 
 
+def test_fetch_profile_returns_first_document(monkeypatch):
+    monkeypatch.setenv("NIGHTSCOUT_URL", "https://example.com")
+    payload = [{"defaultProfile": "Default", "store": {"Default": {"dia": "5"}}}]
+
+    seen_params = []
+    monkeypatch.setattr(
+        ns.requests,
+        "get",
+        lambda *a, **k: (seen_params.append(k["params"]), FakeResponse(payload))[1],
+    )
+
+    result = ns.fetch_profile()
+    assert result == payload[0]
+    assert seen_params[0]["count"] == 1
+
+
+def test_fetch_profile_handles_empty_response(monkeypatch):
+    monkeypatch.setenv("NIGHTSCOUT_URL", "https://example.com")
+    monkeypatch.setattr(ns.requests, "get", lambda *a, **k: FakeResponse([]))
+
+    assert ns.fetch_profile() == {}
+
+
 def test_paginated_get_uses_created_at_field_for_treatments_cursor(monkeypatch):
     """Losstaande, gerichte assertie op het daadwerkelijke queryparameter-veld
     — moet `find[created_at][$lte]` zijn, nooit `find[date][$lte]`, voor het