feat: multi-language interface (zh-CN/zh-TW/en/ja), multilingual offline changelog, settings robustness

i18n
- shared/i18n: dependency-free t() with flat per-namespace dictionaries
  (common/settings/workspace/terminal/ssh/panels/main), zh-CN fallback
- language picker in Settings -> System; antd ConfigProvider locale follows it
- main process tracks the language too: tray menu, close prompt, ssh/sftp/
  zmodem errors and the log TUI marker are translated; tray rebuilds on change

changelog
- CHANGELOG.md (zh-CN canonical) + .zh-TW/.en/.ja, bundled via ?raw and read
  per interface language with per-version fallback to zh-CN (no network)
- sync-changelog.cjs merges RELEASE_NOTES[.<lang>].md per release; release.cjs
  refuses to publish without a zh-CN entry for the version

settings robustness
- closeAction 'ask' survives the sanitizer (was silently coerced to 'tray',
  which made the 'ask every time' option dead)
- highlight rules are repaired instead of dropped: string priority, 0/1
  enabled, missing fg colour; unknown fields preserved
- load-time warnings are written to settings-warnings.log (deduped, capped)

terminal/UI
- configurable terminal toolbar: open working directory (default on), session
  log recording (off), open logs folder (off)
- global shortcut field records key combos (modifier or F-key required)
- input suggestions + command history default to off, with a one-time reset
  migration for existing installs
- settings dialog scrolling fixed (antd v6 renamed the tabs container), theme
  gallery nested scrollbar removed, joined segmented pickers with readable
  selected-state text

tests: settings-store.mjs (15 checks) added; commands-store.mjs updated for
the new off-by-default history setting

src/shared/i18n/dicts/en/common.ts

@@ -0,0 +1,17 @@
+/** Namespace: common (i18n plumbing, generic buttons/status). Owner: i18n infrastructure. */
+const common: Record<string, string> = {
+  'common.ok': 'OK',
+  'common.cancel': 'Cancel',
+  'common.close': 'Close',
+  'common.save': 'Save',
+  'common.delete': 'Delete',
+  'common.edit': 'Edit',
+  'common.add': 'Add',
+  'common.copy': 'Copy',
+  'common.paste': 'Paste',
+  'common.reset': 'Reset to defaults',
+  'common.language': 'Language',
+  'common.languageDesc': 'Switches the interface language immediately; saved permanently.'
+}
+
+export default common