Cut Garmin sync API volume; dashboard/health/records/UI improvements

Garmin Connect sync:
- Incremental syncs now re-fetch only a 1-day buffer (yesterday + today)
  instead of the full lookback window every run. Full lookback applies on
  the first sync only. Cuts steady-state API calls ~10x.
- Beat interval is now configurable via GARMIN_SYNC_INTERVAL_MINUTES and
  surfaced to the UI; the sync toggle is relabelled to the real cadence.

Frontend:
- Collapsible sidebar; clearer logged-in user + role display.
- Unified Body Battery colouring between dashboard and health (shared util).
- Sleep score trend chart on health page.
- Segments + medals on the dashboard's most-recent activity.
- Segments tab on the Records page.

Repo hygiene: add .gitignore, untrack committed __pycache__/*.pyc.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

frontend/src/pages/HealthPage.jsx

@@ -7,6 +7,7 @@ import {
 import { format, subDays } from 'date-fns'
 import api from '../utils/api'
 import { formatSleep, sportIcon } from '../utils/format'
+import { BB_INFERRED_COLOR, BB_INFERRED_LABEL, bbLevelColor, inferBBType } from '../utils/bodyBattery'
 
 const RANGES = [
   { label: '1W',  days: 7 },
@@ -181,37 +182,6 @@ function IntradayHrChart({ values }) {
 
 // ── Body Battery ─────────────────────────────────────────────────────────────
 
-const BB_INFERRED_COLOR = {
-  sleep:    '#4f46e5',
-  rest:     '#0d9488',
-  activity: '#f97316',
-  stable:   '#374151',
-}
-const BB_INFERRED_LABEL = {
-  sleep:    'Sleep',
-  rest:     'Rest',
-  activity: 'Active/Stress',
-  stable:   'Stable',
-}
-
-function bbLevelColor(level) {
-  if (level == null) return '#6b7280'
-  if (level >= 75) return '#3b82f6'
-  if (level >= 50) return '#22c55e'
-  if (level >= 25) return '#f59e0b'
-  return '#ef4444'
-}
-
-function inferBBType(tsMs, level, prevLevel, sleepStartMs, sleepEndMs) {
-  const inSleep = sleepStartMs != null && sleepEndMs != null && tsMs >= sleepStartMs && tsMs <= sleepEndMs
-  if (inSleep) return 'sleep'
-  if (prevLevel != null) {
-    if (level > prevLevel + 0.3) return 'rest'
-    if (level < prevLevel - 0.3) return 'activity'
-  }
-  return 'stable'
-}
-
 function ActivityRefLabel({ viewBox, icon }) {
   if (!viewBox) return null
   const { x, y, width = 0 } = viewBox
@@ -1052,6 +1022,21 @@ export default function HealthPage() {
               </div>
             </div>
 
+            {metrics.some(d => d.sleep_score != null) && (
+              <div className="bg-gray-900 rounded-xl border border-gray-800 p-4">
+                <h3 className="text-sm font-medium text-gray-300 mb-3">Sleep Score</h3>
+                <MetricChart data={metrics} dataKey="sleep_score" color="#818cf8"
+                  formatter={v => Math.round(v)}
+                  domain={[0, 100]}
+                  connectNulls showDots
+                  selectedDate={selDateForCharts} onDayClick={handleDayClick}
+                  referenceLines={[
+                    { y: 80, stroke: '#22c55e', strokeDasharray: '3 3', label: { value: 'Good', position: 'insideTopRight', fill: '#22c55e', fontSize: 9 } },
+                  ]}
+                />
+              </div>
+            )}
+
             <div className="bg-gray-900 rounded-xl border border-gray-800 p-4">
               <WeightChart
                 data={metrics}