feat(HDSSettings): memory-only mode when not hooked

set / setDynamic no longer throw when there is no Pryv connection;
they update the in-memory cache only (so subsequent get() reads back
the value). Useful for standalone demos that don't bind to an account
but still want the settings panel to drive the UI.

Pryv-bound flow is unchanged: once hookToConnection / hookToApplication
runs, writes go through to events.create / events.update as before.

Existing tests HDSS-S3 / HDSD10 updated from "throws when not hooked"
to "memory-only when not hooked".

Author: perki

tests/HDSSettings.test.js

@@ -130,11 +130,11 @@ describe('[HDSS] HDSSettings', function () {
       assert.deepStrictEqual(updateCall.params.update, { content: 'dark' });
     });
 
-    it('[HDSS-S3] throws when not hooked', async () => {
-      await assert.rejects(
-        () => HDSSettings.set('theme', 'dark'),
-        /hookToApplication|hookToConnection/
-      );
+    it('[HDSS-S3] set without hook is memory-only (no Pryv write, value cached)', async () => {
+      // Reset singleton state — no connection means memory-only mode.
+      // The call must not throw and a subsequent get() must return the value.
+      await HDSSettings.set('theme', 'dark');
+      assert.strictEqual(HDSSettings.get('theme'), 'dark');
     });
 
     it('[HDSS-S4] displayName uses same set/get as other settings', async () => {
@@ -313,10 +313,14 @@ describe('[HDSD] HDSSettings dynamic settings', function () {
     );
   });
 
-  it('[HDSD10] setDynamic throws when not hooked', async () => {
+  it('[HDSD10] setDynamic without hook is memory-only (no Pryv write, value cached)', async () => {
+    // Memory-only mode: no connection, no error, get() reads back the value.
+    await HDSSettings.setDynamic('preferred-display-wellbeing-mood', 'billings');
+    assert.strictEqual(HDSSettings.get('preferred-display-wellbeing-mood'), 'billings');
+    // Unknown prefix still throws.
     await assert.rejects(
-      () => HDSSettings.setDynamic('preferred-display-wellbeing-mood', 'billings'),
-      /hookToApplication|hookToConnection/
+      () => HDSSettings.setDynamic('not-a-known-prefix', 'foo'),
+      /Unknown dynamic setting prefix/
     );
   });
 });

ts/settings/HDSSettings.ts

@@ -216,10 +216,15 @@ const HDSSettings = {
 
   /**
    * Set a typed setting value — persists to HDS server and updates cache.
+   * When not hooked (no Pryv connection), accepts the value into the
+   * in-memory cache only (memory-only mode — useful for standalone demos
+   * where settings don't need to survive the session).
    */
   async set<K extends SettingKey> (key: K, value: SettingsValues[K]): Promise<void> {
     if (!_connection || !_streamId) {
-      throw new Error('HDSSettings: call hookToApplication() or hookToConnection() first');
+      _values[key] = value;
+      applySideEffects(_values, key);
+      return;
     }
 
     const eventType = SETTING_TYPES[key];
@@ -249,15 +254,22 @@ const HDSSettings = {
    * Set a dynamic setting value — persists to HDS server.
    * Key must match a known prefix (e.g. 'preferred-display-wellbeing-mood').
    * Pass null to delete the setting.
+   * When not hooked (no Pryv connection), accepts the value into the
+   * in-memory map only (memory-only mode — useful for standalone demos).
    */
   async setDynamic (key: string, value: any): Promise<void> {
-    if (!_connection || !_streamId) {
-      throw new Error('HDSSettings: call hookToApplication() or hookToConnection() first');
-    }
-
     const dp = findDynamicPrefix(key);
     if (!dp) throw new Error(`Unknown dynamic setting prefix for key: "${key}"`);
 
+    if (!_connection || !_streamId) {
+      if (value === null || value === undefined) {
+        delete _dynamicValues[key];
+      } else {
+        _dynamicValues[key] = value;
+      }
+      return;
+    }
+
     const existing = _dynamicCache[key];
 
     if (value === null || value === undefined) {