perf(desktop): add Vite code splitting and terser minification

desktop/frontend/vite.config.ts

@@ -21,6 +21,37 @@ export default defineConfig({
     outDir: "dist",
     emptyOutDir: true,
     target: "es2021",
+    // Use terser for smaller output (esbuild is faster to build but produces
+    // larger bundles). Disabled for dev builds via the default.
+    minify: "terser",
+    terserOptions: {
+      compress: {
+        drop_console: true, // strip console.log in production
+        passes: 2,          // two compression passes for better tree-shaking
+      },
+    },
+    rollupOptions: {
+      output: {
+        // Manual chunk splitting: keep the heavy markdown/math/code pipeline
+        // in a separate chunk so it can be cached independently from the
+        // app shell. The vendor chunk splits react+react-dom (stable, rarely
+        // changes) from the markdown stack (changes more often).
+        manualChunks: {
+          "vendor-react": ["react", "react-dom"],
+          "vendor-markdown": [
+            "react-markdown",
+            "remark-gfm",
+            "remark-math",
+            "rehype-katex",
+            "katex",
+          ],
+          "vendor-highlight": ["highlight.js"],
+        },
+      },
+    },
+    // Raise the warning limit — the markdown vendor chunk is legitimately large
+    // (katex alone is ~300KB). The manual split ensures it's cached separately.
+    chunkSizeWarningLimit: 600,
   },
   server: {
     // Bind IPv4 — unset host listens on ::1, and the Wails dev proxy's [::1]