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

docs/workflow/verification.md

@@ -66,7 +66,7 @@ bun run docs:build
   Content checks run inside the electron-builder afterPack hook. See the
   [release guide](../RELEASING.md#package-contents-checks) for the
   installed-app verification checklist.
-- Dictionary backend windows: after a full build, run `xvfb-run -a bun run test:dictionary:electron` on headless Linux. It uses temporary profiles to check both named settings commands, backend session isolation, the overlay's external-link bridge, and Hachidori's native dictionary parser.
+- Dictionary backend windows: after a full build, run `xvfb-run -a bun run test:dictionary:electron` on headless Linux (CI runs it in the Linux E2E job). It uses temporary profiles to check both named settings commands, backend session isolation, the overlay's external-link bridge, and Hachidori's native dictionary parser.
 - Coverage for the maintained source lane: `bun run test:coverage:src`
 - Deep/local full gate: default handoff gate above