fitness: add GPX upload with map, pace chart, and km splits

Add GPX file upload for cardio exercises in workout history. Parses
GPX track points and stores them in the session. Shows route map
(Leaflet), pace-over-distance chart (Chart.js), and per-km splits
table with color-coded fast/slow pacing. Auto-fills distance and
duration on single-set exercises. Disables Chart.js animations.

package.json

@@ -29,6 +29,7 @@
 		"@sveltejs/vite-plugin-svelte": "^6.1.3",
 		"@testing-library/jest-dom": "^6.9.1",
 		"@testing-library/svelte": "^5.2.9",
+		"@types/leaflet": "^1.9.21",
 		"@types/node": "^22.12.0",
 		"@types/node-cron": "^3.0.11",
 		"@vitest/ui": "^4.0.10",
@@ -48,6 +49,7 @@
 		"chart.js": "^4.5.0",
 		"file-type": "^19.0.0",
 		"ioredis": "^5.9.0",
+		"leaflet": "^1.9.4",
 		"lucide-svelte": "^0.575.0",
 		"mongoose": "^8.0.0",
 		"node-cron": "^4.2.1",