feat(ui): IDEA-style message dialogs, project widget popup and Chinese UI text

Message dialogs: `Dialog` gets an `icon` (question / info / warning / error)
that renders IDEA's alert layout: no title bar, a 32px icon, bold title,
text, checkbox under it. Every confirmation helper (prompt, VCS, services,
project tree, keymap, LSP choices, run, database, Replace All) uses it. Open
Project matches IDEA: "This Window" is the default and has focus. The Code
Analysis and TODO commit checks default to Review.

Project widget: the title bar project button opens a popup like IDEA's
ProjectWidget, with Open… / Clone Repository…, the projects open in other
windows (new `window_open_projects` command) and recent projects, filtered by
typing.

Chinese UI: UI text stays written in English and is translated through a
source-text catalog (`locales/text/zh.json`, about 2300 strings). The UI
primitives (buttons, checkboxes, selects, tabs, dialogs, menus, tooltips,
toasts, settings labels and hints) translate the strings they are given.
Action titles and categories are localised in the registry, and static JSX
text uses `<T>`, so text follows a locale switch without a reload. The
Settings window now syncs the locale too. Settings search matches both
languages.

Claude-Session: https://claude.ai/code/session_01B65qLEKnkeYTGdbwhLpjCu

src/ui/Dialog.module.css

@@ -190,6 +190,65 @@
   outline-offset: 1px;
 }
 
+/* Messages alert (IDEA AlertDialog): 32px icon, bold title, text; draggable anywhere but controls. */
+.message {
+  flex: 1;
+  min-height: 0;
+  overflow: auto;
+  display: flex;
+  gap: 16px;
+  padding: 20px 24px 4px 20px;
+  cursor: default;
+  touch-action: none;
+}
+.messageIcon {
+  flex: none;
+}
+.messageShape {
+  fill: var(--message-icon-color);
+}
+.messageGlyph {
+  stroke: var(--fg-button-primary);
+}
+.question,
+.info {
+  --message-icon-color: var(--info);
+}
+.warning {
+  --message-icon-color: var(--warning);
+}
+.error {
+  --message-icon-color: var(--danger);
+}
+.messageText {
+  flex: 1;
+  min-width: 0;
+  display: flex;
+  flex-direction: column;
+  gap: 8px;
+  padding-top: 4px;
+}
+.messageTitle {
+  color: var(--fg-strong);
+  font-weight: 600;
+}
+.messageBody {
+  color: var(--fg-strong);
+  line-height: 1.5;
+  overflow-wrap: anywhere;
+  white-space: pre-line;
+}
+.messageExtra {
+  display: flex;
+  flex-direction: column;
+  align-items: flex-start;
+  gap: 8px;
+  margin-top: 8px;
+}
+.messageFooter {
+  padding: 16px 24px 20px;
+}
+
 @keyframes rise {
   from {
     opacity: 0;