feat: add about and help panels, donate button, and live setting update (#48)

### Explanation

_No response_

### Issue

Closes #26 Closes #27

### Attestations

- [ ] I have read and agree to the [Code of Conduct](https://docs.nhcarrigan.com/community/coc/)
- [ ] I have read and agree to the [Community Guidelines](https://docs.nhcarrigan.com/community/guide/).
- [ ] My contribution complies with the [Contributor Covenant](https://docs.nhcarrigan.com/dev/covenant/).

### Dependencies

- [ ] I have pinned the dependencies to a specific patch version.

### Style

- [ ] I have run the linter and resolved any errors.
- [ ] My pull request uses an appropriate title, matching the conventional commit standards.
- [ ] My scope of feat/fix/chore/etc. correctly matches the nature of changes in my pull request.

### Tests

- [ ] My contribution adds new code, and I have added tests to cover it.
- [ ] My contribution modifies existing code, and I have updated the tests to reflect these changes.
- [ ] All new and existing tests pass locally with my changes.
- [ ] Code coverage remains at or above the configured threshold.

### Documentation

_No response_

### Versioning

_No response_

Reviewed-on: #48
Co-authored-by: Naomi Carrigan <commits@nhcarrigan.com>
Co-committed-by: Naomi Carrigan <commits@nhcarrigan.com>

src/lib/stores/notifications.ts

@@ -1,22 +1,23 @@
-import { derived } from "svelte/store";
 import { configStore } from "./config";
 import { soundPlayer } from "$lib/notifications";
 
-// Sync notification settings with config
-export const notificationSettings = derived(configStore.config, ($config) => {
-  soundPlayer.setEnabled($config.notifications_enabled);
-  soundPlayer.setGlobalVolume($config.notification_volume);
+let unsubscribe: (() => void) | null = null;
 
-  return {
-    enabled: $config.notifications_enabled,
-    volume: $config.notification_volume,
-  };
-});
+// Initialize notification settings sync - call this once on app startup
+export function initNotificationSync() {
+  // Prevent duplicate subscriptions
+  if (unsubscribe) return;
 
-// Helper to update notification settings
-export async function updateNotificationSettings(enabled: boolean, volume: number) {
-  await configStore.updateConfig({
-    notifications_enabled: enabled,
-    notification_volume: volume,
+  unsubscribe = configStore.config.subscribe(($config) => {
+    soundPlayer.setEnabled($config.notifications_enabled);
+    soundPlayer.setGlobalVolume($config.notification_volume);
   });
 }
+
+// Cleanup function if needed
+export function cleanupNotificationSync() {
+  if (unsubscribe) {
+    unsubscribe();
+    unsubscribe = null;
+  }
+}