fix(client): declare browser-only externals as devDependencies

react, react-dom, shiki, katex, clsx, the micromark and mdast families and nine
more reach only browser artifacts, which resolve nothing on a user's machine.
Moving 79 declarations out of dependencies and non-optional peerDependencies
drops 103 tarballs and 6.05 MB from an install of the published CLI.

packages/client/ui-theme/package.json

@@ -54,8 +54,7 @@
     "@deepseek-ai/dsh-client-ui-settings": "workspace:^",
     "@deepseek-ai/dsh-client-ui-slots": "workspace:^",
     "@deepseek-ai/dsh-host-webserver": "workspace:^",
-    "@deepseek-ai/dsh-invariants": "workspace:^",
-    "react": "^18.2.0"
+    "@deepseek-ai/dsh-invariants": "workspace:^"
   },
   "devDependencies": {
     "@deepseek-ai/cordis": "workspace:^",
@@ -69,6 +68,7 @@
     "@deepseek-ai/dsh-host-webserver": "workspace:^",
     "@deepseek-ai/dsh-invariants": "workspace:^",
     "@types/react": "~18.3.1",
+    "clsx": "^2.0.0",
     "react": "^18.2.0"
   },
   "files": [
@@ -84,7 +84,6 @@
   },
   "dependencies": {
     "@deepseek-ai/dsh-settings": "workspace:^",
-    "clsx": "^2.0.0",
     "@deepseek-ai/schemastery": "workspace:^"
   }
 }