add Trends page: GMI trend, overnight/daytime, weekday pattern, bolus, site-age (FR7, FR8)

reporting.py gains overnight_daytime_split, day_of_week_pattern,
bolus_stats, and site_interval_stats. The last two are explicitly scoped
to bolus-only insulin (no basal reconstruction) since that needs the
Nightscout profile, which is the separate profile-tuning feature's
territory — documented as a caveat in both the UI and the design doc.

Co-Authored-By: Claude Sonnet 5 <[email protected]>

pages/7_Trends.py

@@ -0,0 +1,118 @@
+import plotly.graph_objects as go
+import requests
+import streamlit as st
+
+from auth import require_auth
+from data_processing import classify_treatments
+from nightscout_client import NightscoutConfigError
+from reporting import (
+    bolus_stats,
+    day_of_week_pattern,
+    gmi_percent,
+    overnight_daytime_split,
+    site_interval_stats,
+)
+from ui_common import get_colors, load_range_data, select_period_days
+
+st.set_page_config(page_title="Glucose dashboard — Trends", page_icon="📊", layout="wide")
+require_auth()
+
+st.title("Trends")
+st.caption("Geschat HbA1c (GMI) over tijd en overige statistieken (FR7, FR8).")
+
+start, end, days = select_period_days(default_label="90 dagen")
+
+try:
+    glucose, treatments = load_range_data(start, end)
+except NightscoutConfigError as exc:
+    st.error(str(exc))
+    st.stop()
+except (requests.RequestException, ValueError) as exc:
+    st.error(f"Kon geen data ophalen van Nightscout: {exc}")
+    st.stop()
+
+if glucose.empty:
+    st.info("Geen glucosemetingen gevonden in deze periode.")
+    st.stop()
+
+colors = get_colors()
+events = classify_treatments(treatments)
+
+# --- FR7: geschat HbA1c (GMI) per maand ------------------------------------
+st.subheader("Geschat HbA1c (GMI) per maand")
+monthly = glucose.copy()
+monthly["month"] = monthly["timestamp"].dt.to_period("M").astype(str)
+monthly_gmi = monthly.groupby("month")["mmol"].mean().apply(gmi_percent)
+
+if len(monthly_gmi) >= 1:
+    fig = go.Figure(
+        go.Bar(x=monthly_gmi.index, y=monthly_gmi.to_numpy(), marker_color=colors["glucose"])
+    )
+    fig.update_layout(
+        paper_bgcolor="rgba(0,0,0,0)",
+        plot_bgcolor="rgba(0,0,0,0)",
+        font_color=colors["text"],
+        height=280,
+        margin={"l": 10, "r": 10, "t": 10, "b": 10},
+        yaxis={"title": "GMI (%)", "gridcolor": colors["grid"]},
+        xaxis={"title": "Maand", "gridcolor": colors["grid"]},
+    )
+    st.plotly_chart(fig, width="stretch")
+st.caption("GMI is een schatting (Bergenstal et al. 2018), geen labwaarde.")
+
+# --- FR8: nacht vs. overdag --------------------------------------------------
+st.subheader("Nacht (00:00-06:00) vs. overdag")
+split = overnight_daytime_split(glucose)
+col1, col2 = st.columns(2)
+col1.metric("Tijd in bereik 's nachts", f"{split['overnight']['in_range']:.0f}%")
+col2.metric("Tijd in bereik overdag", f"{split['daytime']['in_range']:.0f}%")
+
+# --- FR8: patroon per weekdag -------------------------------------------------
+st.subheader("Patroon per weekdag")
+weekday_df = day_of_week_pattern(glucose)
+weekday_plot = weekday_df.dropna(subset=["mean_mmol"])
+if not weekday_plot.empty:
+    fig = go.Figure(
+        go.Bar(x=weekday_plot["weekday"], y=weekday_plot["mean_mmol"], marker_color=colors["glucose"])
+    )
+    fig.update_layout(
+        paper_bgcolor="rgba(0,0,0,0)",
+        plot_bgcolor="rgba(0,0,0,0)",
+        font_color=colors["text"],
+        height=280,
+        margin={"l": 10, "r": 10, "t": 10, "b": 10},
+        yaxis={"title": "Gem. glucose (mmol/L)", "gridcolor": colors["grid"]},
+        xaxis={"gridcolor": colors["grid"]},
+    )
+    st.plotly_chart(fig, width="stretch")
+
+# --- FR8: bolus-insuline --------------------------------------------------
+st.subheader("Bolus-insuline")
+st.caption(
+    "Alleen bolusinsuline (maaltijd/correctie/combo/SMB) — basaalinsuline vereist "
+    "profielgegevens en is hier niet in verwerkt (zie docs/design-reporting.md)."
+)
+bolus = bolus_stats(treatments)
+col1, col2 = st.columns(2)
+col1.metric("Totaal bolus", f"{bolus['total_units']:.1f} E")
+col2.metric("Aantal boluses", bolus["count"])
+if bolus["by_type"]:
+    st.table({"type": list(bolus["by_type"].keys()), "eenheden": list(bolus["by_type"].values())})
+
+# --- FR8: pompsite-leeftijd vs. glucose/insuline ---------------------------
+st.subheader("Pompsite-leeftijd vs. glucose en insuline")
+st.caption(
+    "Statistieken per interval tussen opeenvolgende pompwissels — een benadering "
+    "(zonder basaalinsuline) van of insulinebehoefte samenhangt met de leeftijd "
+    "van de pompsite."
+)
+site_stats = site_interval_stats(glucose, treatments, events["site_changes"])
+if site_stats.empty:
+    st.info("Geen pompwissels gevonden in deze periode.")
+else:
+    display = site_stats.copy()
+    display["start"] = display["start"].dt.strftime("%d-%m-%Y")
+    display["end"] = display["end"].dt.strftime("%d-%m-%Y")
+    st.dataframe(display, width="stretch", hide_index=True)
+
+st.caption(f"Periode: {start.strftime('%d-%m-%Y')} t/m {end.strftime('%d-%m-%Y')}")