feat: add baseline range (min/mean/max) to vegetation and cropland chart data

Track per-year means during the baseline STAC loop and expose them as
baseline_range_min/mean/max scalars in _build_chart_data when 2+ years
are available. Adds test_indicator_vegetation.py and extends
test_indicator_cropland.py with range assertions.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

app/indicators/cropland.py

@@ -45,7 +45,7 @@ class CroplandIndicator(BaseIndicator):
             else ConfidenceLevel.LOW
         )
 
-        chart_data = self._build_chart_data(baseline_mean, current_mean, time_range)
+        chart_data = self._build_chart_data(baseline_mean, current_mean, time_range, getattr(self, '_baseline_yearly_means', None))
 
         if abs_change <= 5:
             headline = f"Cropland vegetation stable ({current_mean:.0f}% cover, ±{abs_change:.0f}pp vs baseline)"
@@ -219,10 +219,16 @@ class CroplandIndicator(BaseIndicator):
 
         # Baseline: pool all years by month, then median per month
         baseline_pool: dict[int, list[float]] = defaultdict(list)
+        baseline_yearly_means: list[float] = []
         for yr in range(baseline_start_year, current_year):
             yr_monthly = await loop.run_in_executor(None, _query_growing_season, yr)
+            yr_medians = []
             for month, vals in yr_monthly.items():
                 baseline_pool[month].extend(vals)
+                if vals:
+                    yr_medians.append(float(np.median(vals)))
+            if yr_medians:
+                baseline_yearly_means.append(float(np.mean(yr_medians)))
 
         # Month-matched comparison: only growing-season months with data in BOTH periods
         baseline_medians = []
@@ -239,6 +245,7 @@ class CroplandIndicator(BaseIndicator):
             self._is_placeholder = True
             return self._synthetic()
 
+        self._baseline_yearly_means = baseline_yearly_means
         return (
             float(np.mean(baseline_medians)),
             float(np.mean(current_medians)),
@@ -271,10 +278,16 @@ class CroplandIndicator(BaseIndicator):
 
     @staticmethod
     def _build_chart_data(
-        baseline: float, current: float, time_range: TimeRange
+        baseline: float, current: float, time_range: TimeRange,
+        baseline_yearly_means: list[float] | None = None,
     ) -> dict[str, Any]:
-        return {
+        data: dict[str, Any] = {
             "dates": [str(time_range.start.year - 1), str(time_range.end.year)],
             "values": [round(baseline, 1), round(current, 1)],
             "label": "Vegetation cover (%)",
         }
+        if baseline_yearly_means and len(baseline_yearly_means) >= 2:
+            data["baseline_range_mean"] = round(float(np.mean(baseline_yearly_means)), 1)
+            data["baseline_range_min"] = round(float(min(baseline_yearly_means)), 1)
+            data["baseline_range_max"] = round(float(max(baseline_yearly_means)), 1)
+        return data

app/indicators/vegetation.py

@@ -40,7 +40,7 @@ class VegetationIndicator(BaseIndicator):
             else ConfidenceLevel.MODERATE if n_months >= 3
             else ConfidenceLevel.LOW
         )
-        chart_data = self._build_chart_data(baseline_mean, current_mean, time_range)
+        chart_data = self._build_chart_data(baseline_mean, current_mean, time_range, getattr(self, '_baseline_yearly_means', None))
 
         if abs_change <= 5:
             headline = f"Vegetation cover stable ({current_mean:.0f}% cover, ±{abs_change:.0f}pp vs baseline)"
@@ -200,10 +200,16 @@ class VegetationIndicator(BaseIndicator):
         current_monthly = await loop.run_in_executor(None, _query_monthly, current_year)
 
         baseline_pool: dict[int, list[float]] = defaultdict(list)
+        baseline_yearly_means: list[float] = []
         for yr in range(baseline_start_year, current_year):
             yr_monthly = await loop.run_in_executor(None, _query_monthly, yr)
+            yr_medians = []
             for month, vals in yr_monthly.items():
                 baseline_pool[month].extend(vals)
+                if vals:
+                    yr_medians.append(float(np.median(vals)))
+            if yr_medians:
+                baseline_yearly_means.append(float(np.mean(yr_medians)))
 
         baseline_medians = []
         current_medians = []
@@ -219,6 +225,7 @@ class VegetationIndicator(BaseIndicator):
             self._is_placeholder = True
             return self._synthetic()
 
+        self._baseline_yearly_means = baseline_yearly_means
         return (
             float(np.mean(baseline_medians)),
             float(np.mean(current_medians)),
@@ -250,10 +257,16 @@ class VegetationIndicator(BaseIndicator):
 
     @staticmethod
     def _build_chart_data(
-        baseline: float, current: float, time_range: TimeRange
+        baseline: float, current: float, time_range: TimeRange,
+        baseline_yearly_means: list[float] | None = None,
     ) -> dict[str, Any]:
-        return {
+        data: dict[str, Any] = {
             "dates": [str(time_range.start.year - 1), str(time_range.end.year)],
             "values": [round(baseline, 1), round(current, 1)],
             "label": "Vegetation cover (%)",
         }
+        if baseline_yearly_means and len(baseline_yearly_means) >= 2:
+            data["baseline_range_mean"] = round(float(np.mean(baseline_yearly_means)), 1)
+            data["baseline_range_min"] = round(float(min(baseline_yearly_means)), 1)
+            data["baseline_range_max"] = round(float(max(baseline_yearly_means)), 1)
+        return data

tests/test_indicator_cropland.py

@@ -169,3 +169,48 @@ def test_classify_boundary():
     assert ind._classify(-5.1) == StatusLevel.AMBER
     assert ind._classify(-15) == StatusLevel.AMBER     # boundary
     assert ind._classify(-15.1) == StatusLevel.RED
+
+
+# ---------------------------------------------------------------------------
+# Baseline range in chart data
+# ---------------------------------------------------------------------------
+
+def test_build_chart_data_includes_baseline_range():
+    from app.indicators.cropland import CroplandIndicator
+    from datetime import date
+    from app.models import TimeRange
+    tr = TimeRange(start=date(2025, 1, 1), end=date(2025, 12, 31))
+    result = CroplandIndicator._build_chart_data(
+        baseline=40.0, current=42.0, time_range=tr,
+        baseline_yearly_means=[38.0, 40.0, 42.0],
+    )
+    assert "baseline_range_mean" in result
+    assert "baseline_range_min" in result
+    assert "baseline_range_max" in result
+    assert result["baseline_range_min"] == 38.0
+    assert result["baseline_range_max"] == 42.0
+
+
+def test_build_chart_data_no_baseline_range_when_absent():
+    from app.indicators.cropland import CroplandIndicator
+    from datetime import date
+    from app.models import TimeRange
+    tr = TimeRange(start=date(2025, 1, 1), end=date(2025, 12, 31))
+    result = CroplandIndicator._build_chart_data(
+        baseline=40.0, current=42.0, time_range=tr,
+    )
+    assert "baseline_range_mean" not in result
+    assert "baseline_range_min" not in result
+    assert "baseline_range_max" not in result
+
+
+def test_build_chart_data_no_baseline_range_when_single_year():
+    from app.indicators.cropland import CroplandIndicator
+    from datetime import date
+    from app.models import TimeRange
+    tr = TimeRange(start=date(2025, 1, 1), end=date(2025, 12, 31))
+    result = CroplandIndicator._build_chart_data(
+        baseline=40.0, current=42.0, time_range=tr,
+        baseline_yearly_means=[40.0],
+    )
+    assert "baseline_range_mean" not in result

tests/test_indicator_vegetation.py

@@ -0,0 +1,68 @@
+"""Tests for the D2 Vegetation & Forest Cover indicator."""
+from __future__ import annotations
+
+from datetime import date
+
+import pytest
+
+from app.indicators.vegetation import VegetationIndicator
+from app.models import TimeRange
+
+
+# ---------------------------------------------------------------------------
+# Baseline range in chart data
+# ---------------------------------------------------------------------------
+
+def test_build_chart_data_includes_baseline_range():
+    tr = TimeRange(start=date(2025, 1, 1), end=date(2025, 12, 31))
+    result = VegetationIndicator._build_chart_data(
+        baseline=35.0, current=38.0, time_range=tr,
+        baseline_yearly_means=[32.0, 35.0, 38.0, 34.0, 36.0],
+    )
+    assert "baseline_range_mean" in result
+    assert "baseline_range_min" in result
+    assert "baseline_range_max" in result
+    assert result["baseline_range_min"] == 32.0
+    assert result["baseline_range_max"] == 38.0
+    assert result["baseline_range_min"] <= result["baseline_range_mean"] <= result["baseline_range_max"]
+
+
+def test_build_chart_data_no_baseline_range_when_absent():
+    tr = TimeRange(start=date(2025, 1, 1), end=date(2025, 12, 31))
+    result = VegetationIndicator._build_chart_data(
+        baseline=35.0, current=38.0, time_range=tr,
+    )
+    assert "baseline_range_mean" not in result
+    assert "baseline_range_min" not in result
+    assert "baseline_range_max" not in result
+
+
+def test_build_chart_data_no_baseline_range_when_single_year():
+    tr = TimeRange(start=date(2025, 1, 1), end=date(2025, 12, 31))
+    result = VegetationIndicator._build_chart_data(
+        baseline=35.0, current=38.0, time_range=tr,
+        baseline_yearly_means=[35.0],
+    )
+    assert "baseline_range_mean" not in result
+
+
+def test_build_chart_data_baseline_range_mean_is_rounded():
+    tr = TimeRange(start=date(2025, 1, 1), end=date(2025, 12, 31))
+    result = VegetationIndicator._build_chart_data(
+        baseline=35.0, current=38.0, time_range=tr,
+        baseline_yearly_means=[33.33, 36.67],
+    )
+    assert isinstance(result["baseline_range_mean"], float)
+    # Should be rounded to 1 decimal place
+    assert result["baseline_range_mean"] == round(result["baseline_range_mean"], 1)
+
+
+def test_build_chart_data_base_fields_always_present():
+    tr = TimeRange(start=date(2025, 1, 1), end=date(2025, 12, 31))
+    result = VegetationIndicator._build_chart_data(
+        baseline=35.0, current=38.0, time_range=tr,
+    )
+    assert "dates" in result
+    assert "values" in result
+    assert "label" in result
+    assert result["values"] == [35.0, 38.0]