fix(dictionary): restore Anki proxy marker when Hachidori sync fails

- Revert the proxy marker to its previous value when every settings write attempt fails, so it no longer claims a server that was never written
- Add a test for the all-writes-fail path
- Retry Windows managed runtime cleanup in the test while bun.exe stays locked after exit

src/core/services/tokenizer/hachidori-anki-settings.test.ts

@@ -36,11 +36,12 @@ async function harness(
   vm.runInContext(
     `
     let options = { ...HDReaderOptions.normaliseOptions({ anki: __initialAnki }), revision: 1 };
-    let writes = 0, online = true, race = false, proxy = null;
+    let writes = 0, online = true, race = false, proxy = null, failWrites = false;
     const readOptions = async () => structuredClone(options);
     globalThis.__subminerSetAnkiProxyUrl = async value => { const old = proxy; proxy = value; return old; };
     const send = async (type, request, target) => {
       if (type !== 'hd_options_write' || target !== 'hoshidicts-worker') throw Error('Unexpected request');
+      if (failWrites) throw Error('offline');
       if (race) {
         race = false;
         options.anki.templates[0].tags = options.anki.tags = ['User edit'];
@@ -164,6 +165,13 @@ test('re-reads concurrent settings edits before retrying its revisioned write',
   assert.equal(await h.run('options.anki.model'), 'Japanese');
 });
 
+test('restores the previous proxy marker when every settings write fails', async () => {
+  const h = await harness();
+  await h.run(`proxy = 'http://127.0.0.1:9000'; failWrites = true`);
+  await assert.rejects(h.sync(), /offline/);
+  assert.equal(await h.run('proxy'), 'http://127.0.0.1:9000');
+});
+
 test('keeps sentence audio out of captured-audio settings and uses wordAudio first', () => {
   const hints = buildHachidoriAnkiHints({
     fields: { audio: 'SentenceAudio', wordAudio: 'WordAudio' },

src/core/services/tokenizer/hachidori-anki-settings.ts

@@ -112,7 +112,11 @@ export const HACHIDORI_ANKI_SETTINGS_SCRIPT = String.raw`
           }, 'hoshidicts-worker');
           return { updated: changed, matched: !pending, pending };
         } catch (error) {
-          if (attempt > 0) throw error;
+          if (attempt > 0) {
+            // The server was never written, so the marker must not claim it.
+            await globalThis.__subminerSetAnkiProxyUrl(previousProxy);
+            throw error;
+          }
           // Re-read after a concurrent settings save before filling anything.
         }
       }

src/main/runtime/managed-launcher.test.ts

@@ -372,12 +372,19 @@ test('Windows stages a new runtime version while the prior Bun executable is run
       await exited;
     }
   }
+  // Windows can keep bun.exe locked briefly after the exit event; cleanup
+  // skips locked runtimes, so retry the way the next launch would.
+  const firstDirectory = path.dirname(first.bunPath);
+  for (let attempt = 0; attempt < 30; attempt += 1) {
     cleanupOldWindowsManagedRuntimes({
       platform: 'win32',
       localAppData: root,
       appVersion: '2.0.0',
     });
-  assert.equal(fs.existsSync(path.dirname(first.bunPath)), false);
+    if (!fs.existsSync(firstDirectory)) break;
+    await new Promise((resolve) => setTimeout(resolve, 100));
+  }
+  assert.equal(fs.existsSync(firstDirectory), false);
   assert.ok(fs.existsSync(expectedSecond.bunPath));
 });