fix(desktop): one unreadable value in desktop-settings.json no longer resets every desktop setting

apps/desktop/src/settings/DesktopAppSettings.test.ts

@@ -170,6 +170,9 @@ describe("DesktopSettings", () => {
             "tailscaleServeEnabled": true,
             "tailscaleServePort": 8443,
             "mainWindowBounds": { "x": 120, "y": 80, "width": 1280, "height": 900 },
+            // Values this build cannot read fall back per field, not for the whole file.
+            "updateChannel": "beta",
+            "wslOnly": "yes",
           }\n`,
         );
 

apps/desktop/src/settings/DesktopAppSettings.ts

@@ -14,6 +14,7 @@ import * as Layer from "effect/Layer";
 import * as Option from "effect/Option";
 import * as Path from "effect/Path";
 import * as Schema from "effect/Schema";
+import * as Struct from "effect/Struct";
 import * as SynchronizedRef from "effect/SynchronizedRef";
 
 import * as DesktopEnvironment from "../app/DesktopEnvironment.ts";
@@ -104,7 +105,21 @@ const DesktopSettingsDocument = Schema.Struct({
 type DesktopSettingsDocument = typeof DesktopSettingsDocument.Type;
 type Mutable<T> = { -readonly [K in keyof T]: T[K] };
 
-const DesktopSettingsJson = fromLenientJson(DesktopSettingsDocument);
+interface DropUnreadableKey extends Struct.Lambda {
+  <S extends Schema.Top>(field: S): Schema.middlewareDecoding<S, S["DecodingServices"]>;
+  readonly "~lambda.out": this["~lambda.in"] extends Schema.Top
+    ? Schema.middlewareDecoding<this["~lambda.in"], this["~lambda.in"]["DecodingServices"]>
+    : never;
+}
+// A value this build cannot read drops only its own key, so the rest of the file
+// still loads instead of every setting resetting to defaults.
+const dropUnreadableKey = Struct.lambda<DropUnreadableKey>((field) =>
+  field.pipe(Schema.catchDecoding(() => Effect.succeedNone)),
+);
+
+const DesktopSettingsJson = fromLenientJson(
+  DesktopSettingsDocument.mapFields(Struct.map(dropUnreadableKey)),
+);
 const decodeDesktopSettingsJson = Schema.decodeEffect(DesktopSettingsJson);
 const encodeDesktopSettingsJson = Schema.encodeEffect(DesktopSettingsJson);
 const decodeDesktopWindowBounds = Schema.decodeUnknownOption(DesktopWindowBoundsSchema);