fix(fitness): seed body-part inputs from last record

Placeholders and +/- fallback now use the most recent recorded
value per part; previously placeholders were hardcoded "—" and
+/- bumped from 0. Buttons step by 0.5 cm (manual input still
accepts 0.1 resolution).

package.json

@@ -1,6 +1,6 @@
 {
 	"name": "homepage",
-	"version": "1.40.4",
+	"version": "1.40.5",
 	"private": true,
 	"type": "module",
 	"scripts": {