refactor(gui): copy-free settings shell; ui-settings-general owns ownerless copy

The shell is now a pure composition face: no dictionaries, no locale
dependency, and three new chrome content seats (settings.trigger /
settings.header / settings.close) whose slot content also carries the
accessible names (trigger text, dialog aria-labelledby, visually hidden
close label). ui-settings-general returns as the owner of copy that
belongs to no single feature: chrome content, the General section with
its item slot, and the settings dictionaries. Slot types split homes —
trigger/header/close/section live in the shell contract; the
settings.general.item entry moves to the locale package (the common
dependency of every item registrant), with ui-theme consuming it
through a re-export seam; the verbatim duplicate merges are gone and
the dependency graph is a clean DAG.

packages/client/ui-settings/package.json

@@ -25,8 +25,7 @@
   "dshClient": {
     "inject": [
       "@deepseek-ai/dsh-client-runtime",
-      "@deepseek-ai/dsh-client-ui-sidebar",
-      "@deepseek-ai/dsh-client-locale"
+      "@deepseek-ai/dsh-client-ui-sidebar"
     ],
     "platform": "web"
   },
@@ -47,7 +46,6 @@
     "react": "^18.2.0"
   },
   "devDependencies": {
-    "@deepseek-ai/dsh-client-locale": "workspace:^",
     "@deepseek-ai/dsh-client-runtime": "workspace:^",
     "@deepseek-ai/dsh-client-ui-primitives": "workspace:^",
     "@deepseek-ai/dsh-client-ui-sidebar": "workspace:^",