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/runtime/package.json

@@ -53,10 +53,7 @@
     "@deepseek-ai/dsh-session": "workspace:^",
     "@deepseek-ai/dsh-session-projection": "workspace:^",
     "@deepseek-ai/dsh-session-title": "workspace:^",
-    "@deepseek-ai/dsh-tools": "workspace:^",
-    "immer": "^10.1.1",
-    "react": "^18.2.0",
-    "zustand": "~4.4.7"
+    "@deepseek-ai/dsh-tools": "workspace:^"
   },
   "peerDependencies": {
     "@deepseek-ai/cordis": "workspace:^",
@@ -72,7 +69,10 @@
     "@deepseek-ai/dsh-timeout": "workspace:^",
     "@deepseek-ai/dsh-typert-protocol": "workspace:^",
     "@deepseek-ai/dsh-typert-registry": "workspace:^",
-    "@types/react": "~18.3.1"
+    "@types/react": "~18.3.1",
+    "immer": "^10.1.1",
+    "react": "^18.2.0",
+    "zustand": "~4.4.7"
   },
   "files": [
     "lib/index.js",