fix(hachidori): finish character dictionary imports without keep-alive w

- Close lingering sockets on the one-shot dictionary ZIP server so imports report completion as soon as the archive is read
- Run test:dictionary:electron in the Linux CI E2E job
- Note that annotations and lookups pause during Hachidori imports
- Keep only dictionaryBackend in the Dictionary Lookup settings section
- Move the requestHachidoriSharing import below the license header

src/core/services/tokenizer/yomitan-parser-runtime.ts

@@ -872,6 +872,9 @@ async function serveDictionaryZipOnce<T>(
     }
     return await callback(`http://127.0.0.1:${address.port}${requestPath}`);
   } finally {
+    // The extension's fetch keeps its socket open; close() alone would wait out
+    // Node's keep-alive timeout before the import reports completion.
+    server.closeAllConnections();
     await new Promise<void>((resolve) => server.close(() => resolve()));
   }
 }