fix(playback): keep the saved Embedded MPV player when the mpv check is inconclusive

On Linux native-view the support check runs `mpv --version` by bare name
and waits for the login shell PATH first. Since #1784 that lookup is
asynchronous with a 10 s budget; when it ran out, the check ran on the
inherited PATH and answered a plain `supported: false`. The settings store
took that as a verdict and persisted the default player over a saved
Embedded MPV selection. The main process probed again once the shell
answered, but nothing restored the setting.

`EmbeddedMpvSupport` now carries `inconclusive`. The native service sets it
on a missing mpv while its probe has only seen the inherited PATH; the IPC
handler declares that state before probing and registers the re-probe
before the check, so a throwing check cannot leave it stuck. Every other
answer stays final.

Consumers no longer settle on an inconclusive answer: the settings store
keeps the saved player, and the command palette and the settings search
probe again on their next use instead of caching it for the session.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

libs/workspace/shell/util/src/lib/settings-search/settings-search.service.spec.ts

@@ -142,6 +142,7 @@ describe('SettingsSearchService', () => {
 
         function probeWith(support: {
             supported: boolean;
+            inconclusive?: boolean;
             frameCopyAvailable?: boolean;
         }) {
             const getEmbeddedMpvSupport = jest
@@ -186,6 +187,32 @@ describe('SettingsSearchService', () => {
             );
         });
 
+        it('asks again after an inconclusive answer and keeps the final one', async () => {
+            // A slow login shell: mpv was looked up before its PATH arrived.
+            const getEmbeddedMpvSupport = probeWith({
+                supported: false,
+                inconclusive: true,
+            });
+            const { service } = setup({
+                ...DESKTOP,
+                supportsEmbeddedMpv: true,
+            });
+            const entries = () => service.visibleEntries().map(({ id }) => id);
+
+            await service.ensureEmbeddedMpvSupportLoaded();
+            expect(entries()).not.toContain('embedded-mpv-extra-options');
+
+            // The shell answered meanwhile, and mpv is there.
+            getEmbeddedMpvSupport.mockResolvedValue({
+                platform: 'linux',
+                supported: true,
+            });
+            await service.ensureEmbeddedMpvSupportLoaded();
+            expect(entries()).toContain('embedded-mpv-extra-options');
+            expect(service.ensureEmbeddedMpvSupportLoaded()).toBeUndefined();
+            expect(getEmbeddedMpvSupport).toHaveBeenCalledTimes(2);
+        });
+
         it('does not probe where the runtime has no embedded MPV bridge', () => {
             const getEmbeddedMpvSupport = probeWith({ supported: true });
             const { service } = setup(DESKTOP);

libs/workspace/shell/util/src/lib/settings-search/settings-search.service.ts

@@ -66,7 +66,8 @@ export class SettingsSearchService {
      * searchable. Returns the pending probe, or `undefined` when there is
      * nothing to wait for. Call it lazily (palette open, settings page),
      * never from shell bootstrap: supported desktop builds may load the
-     * native addon while answering.
+     * native addon while answering. An inconclusive answer is used until
+     * the next call, which probes again.
      */
     ensureEmbeddedMpvSupportLoaded(): Promise<void> | undefined {
         if (this.embeddedMpvSupportChecked) {
@@ -88,7 +89,9 @@ export class SettingsSearchService {
             .then((support) => this.embeddedMpvSupport.set(support))
             .catch(() => this.embeddedMpvSupport.set(null))
             .finally(() => {
-                this.embeddedMpvSupportChecked = true;
+                this.embeddedMpvSupportChecked =
+                    !this.embeddedMpvSupport()?.inconclusive;
+                this.embeddedMpvSupportLoad = undefined;
             });
         return this.embeddedMpvSupportLoad;
     }