Fix body battery and intensity minutes Garmin API endpoints

Body Battery:
- Change endpoint from /usersummary-service/stats/bodyBattery/dates/
  to /wellness-service/wellness/bodyBattery/reports/daily
- Parse new response format: array with bodyBatteryValuesArray time series
- Current value = last entry's level (index 2)
- YesterdayLow = min level from yesterday's data

Intensity Minutes:
- Change endpoint from /fitnessstats-service/activity
  to /usersummary-service/stats/im/weekly
- Add date parameter to function signature
- Parse new response format: array with moderateValue/vigorousValue

Endpoints verified against python-garminconnect source code.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/lib/garmin.ts

@@ -109,8 +109,13 @@ export async function fetchBodyBattery(
   oauth2Token: string,
 ): Promise<BodyBatteryData> {
   try {
+    // Calculate yesterday's date for the API request
+    const dateObj = new Date(date);
+    dateObj.setDate(dateObj.getDate() - 1);
+    const yesterday = dateObj.toISOString().split("T")[0];
+
     const response = await fetch(
-      `${GARMIN_API_URL}/usersummary-service/stats/bodyBattery/dates/${date}`,
+      `${GARMIN_API_URL}/wellness-service/wellness/bodyBattery/reports/daily?startDate=${yesterday}&endDate=${date}`,
       {
         headers: getGarminHeaders(oauth2Token),
       },
@@ -132,20 +137,33 @@ export async function fetchBodyBattery(
       );
       return { current: null, yesterdayLow: null };
     }
-    const data = JSON.parse(text);
+    const data = JSON.parse(text) as Array<{
+      date: string;
+      bodyBatteryValuesArray?: Array<[number, string, number, number]>;
+    }>;
 
-    const currentData = data?.bodyBatteryValuesArray?.[0];
-    const current = currentData?.charged ?? null;
+    // Find today's and yesterday's data from the response array
+    const todayData = data?.find((d) => d.date === date);
+    const yesterdayData = data?.find((d) => d.date === yesterday);
 
-    const yesterdayStats = data?.bodyBatteryStatList?.[0];
-    const yesterdayLow = yesterdayStats?.min ?? null;
+    // Current = last value in today's bodyBatteryValuesArray (index 2 is the level)
+    const todayValues = todayData?.bodyBatteryValuesArray ?? [];
+    const current =
+      todayValues.length > 0 ? todayValues[todayValues.length - 1][2] : null;
+
+    // Yesterday low = minimum level in yesterday's bodyBatteryValuesArray
+    const yesterdayValues = yesterdayData?.bodyBatteryValuesArray ?? [];
+    const yesterdayLow =
+      yesterdayValues.length > 0
+        ? Math.min(...yesterdayValues.map((v) => v[2]))
+        : null;
 
     logger.info(
       {
         current,
         yesterdayLow,
-        hasCurrentData: !!currentData,
-        hasYesterdayData: !!yesterdayStats,
+        hasCurrentData: todayValues.length > 0,
+        hasYesterdayData: yesterdayValues.length > 0,
       },
       "Garmin body battery data received",
     );
@@ -161,11 +179,18 @@ export async function fetchBodyBattery(
 }
 
 export async function fetchIntensityMinutes(
+  date: string,
   oauth2Token: string,
 ): Promise<number> {
   try {
+    // Calculate 7 days before the date for weekly range
+    const endDate = date;
+    const startDateObj = new Date(date);
+    startDateObj.setDate(startDateObj.getDate() - 7);
+    const startDate = startDateObj.toISOString().split("T")[0];
+
     const response = await fetch(
-      `${GARMIN_API_URL}/fitnessstats-service/activity`,
+      `${GARMIN_API_URL}/usersummary-service/stats/im/weekly?start=${startDate}&end=${endDate}`,
       {
         headers: getGarminHeaders(oauth2Token),
       },
@@ -173,7 +198,7 @@ export async function fetchIntensityMinutes(
 
     if (!response.ok) {
       logger.warn(
-        { status: response.status, endpoint: "fitnessstats" },
+        { status: response.status, endpoint: "intensityMinutes" },
         "Garmin intensity minutes API error",
       );
       return 0;
@@ -182,24 +207,28 @@ export async function fetchIntensityMinutes(
     const text = await response.text();
     if (!text.startsWith("{") && !text.startsWith("[")) {
       logger.error(
-        { endpoint: "fitnessstats", responseBody: text.slice(0, 1000) },
+        { endpoint: "intensityMinutes", responseBody: text.slice(0, 1000) },
         "Garmin returned non-JSON response",
       );
       return 0;
     }
-    const data = JSON.parse(text);
-    const weeklyTotal = data?.weeklyTotal;
+    const data = JSON.parse(text) as Array<{
+      calendarDate: string;
+      moderateValue?: number;
+      vigorousValue?: number;
+    }>;
 
-    if (!weeklyTotal) {
+    const entry = data?.[0];
+    if (!entry) {
       logger.info(
-        { hasWeeklyTotal: false },
+        { hasData: false },
         "Garmin intensity minutes: no weekly data",
       );
       return 0;
     }
 
-    const moderate = weeklyTotal.moderateIntensityMinutes ?? 0;
-    const vigorous = weeklyTotal.vigorousIntensityMinutes ?? 0;
+    const moderate = entry.moderateValue ?? 0;
+    const vigorous = entry.vigorousValue ?? 0;
     const total = moderate + vigorous;
 
     logger.info(
@@ -210,7 +239,7 @@ export async function fetchIntensityMinutes(
     return total;
   } catch (error) {
     logger.error(
-      { err: error, endpoint: "fitnessstats" },
+      { err: error, endpoint: "intensityMinutes" },
       "Garmin intensity minutes fetch failed",
     );
     return 0;