usage notes switch on the Home screen

gearslip/src/main/java/app/seb3thehacker/gearslip/ui/HomeScreen.kt

@@ -92,6 +92,7 @@ fun HomeScreen(
                 StatusCard(status)
                 Spacer(Modifier.height(16.dp))
                 UpdateCard()
+                UsageNotesHomeCard()
             }
 
             // Sits at the bottom, where a thumb reaches it.

gearslip/src/main/java/app/seb3thehacker/gearslip/ui/UpdateViews.kt

@@ -96,6 +96,8 @@ fun UpdateCard() {
             }
         }
     }
+    // Room before whatever Home shows next; nothing when the card is hidden.
+    Spacer(Modifier.height(16.dp))
 }
 
 /** The Settings row: checks on tap, and carries on to download and install once something is found. */

gearslip/src/main/java/app/seb3thehacker/gearslip/ui/UsageStatsChoices.kt

@@ -152,3 +152,24 @@ private fun Choice(label: String, checked: Boolean, onChange: (Boolean) -> Unit)
         Checkbox(checked = checked, onCheckedChange = null, modifier = Modifier.padding(vertical = 8.dp))
     }
 }
+
+/** Usage notes on Home, always: the switch, and once it's on, what to share. */
+@Composable
+internal fun UsageNotesHomeCard(modifier: Modifier = Modifier) {
+    Column(modifier) {
+        Text(
+            USAGE_STATS_TITLE,
+            style = MaterialTheme.typography.labelLarge,
+            color = MaterialTheme.colorScheme.primary,
+            modifier = Modifier.padding(start = 16.dp, bottom = 4.dp),
+        )
+        Text(
+            "Share a short note after each drive, so the next driver knows whether Gearslip works " +
+                "in their car. No name, account, or location.",
+            style = MaterialTheme.typography.bodyMedium,
+            color = MaterialTheme.colorScheme.onSurfaceVariant,
+            modifier = Modifier.padding(start = 16.dp, end = 16.dp, bottom = 12.dp),
+        )
+        SettingsCard { UsageStatsRows() }
+    }
+}