build(deps): move renderer-only deps to devDependencies, shrink asar 98MB -> 8.1MB

Renderer code is fully bundled by Vite into out/renderer; externalizeDepsPlugin
only applies to main/preload, so renderer packages in 'dependencies' were
shipped twice. Moved to devDependencies: @xterm/*, antd, dockview-react,
react, react-dom, zustand. Kept in dependencies (imported by src/main):
@lydell/node-pty, ssh2, zmodem.js, font-list, electron-updater. undici is
now explicit (release.cjs/download-stats.cjs require it). Also dropped the
dead @xterm/addon-serialize (zero imports anywhere).

Verified: npm test 17/17 green, dist:dir builds, asar node_modules contains
only main-process deps, asarUnpack natives intact, win-unpacked smoke
(window, theme, pty spawn) passes.

package.json

@@ -20,31 +20,31 @@
   },
   "dependencies": {
     "@lydell/node-pty": "^1.2.0-beta.15",
-    "@xterm/addon-fit": "^0.11.0",
-    "@xterm/addon-search": "^0.16.0",
-    "@xterm/addon-serialize": "^0.14.0",
-    "@xterm/addon-webgl": "^0.19.0",
-    "@xterm/xterm": "6.1.0-beta.304",
-    "antd": "^6.6.2",
-    "dockview-react": "^8.2.0",
     "electron-updater": "^6.8.9",
     "font-list": "^2.1.0",
-    "react": "^19.2.8",
-    "react-dom": "^19.2.8",
     "ssh2": "^1.17.0",
-    "zmodem.js": "^0.1.10",
-    "zustand": "^5.0.15"
+    "zmodem.js": "^0.1.10"
   },
   "devDependencies": {
     "@types/node": "^24.0.0",
     "@types/react": "^19.2.0",
     "@types/react-dom": "^19.2.0",
     "@vitejs/plugin-react": "^5.0.0",
+    "@xterm/addon-fit": "^0.11.0",
+    "@xterm/addon-search": "^0.16.0",
+    "@xterm/addon-webgl": "^0.19.0",
+    "@xterm/xterm": "6.1.0-beta.304",
+    "antd": "^6.6.2",
+    "dockview-react": "^8.2.0",
     "electron": "^44.2.0",
     "electron-builder": "^26.15.3",
     "electron-vite": "^5.0.0",
     "esbuild": "^0.25.12",
+    "react": "^19.2.8",
+    "react-dom": "^19.2.8",
     "typescript": "~5.9.0",
-    "vite": "^7.0.0"
+    "undici": "^7.29.1",
+    "vite": "^7.0.0",
+    "zustand": "^5.0.15"
   }
 }