fix(nix): shrink desktop runtime output (#2550)

Package only the traced desktop and daemon runtime graph, preserve required runtime entrypoints, and exclude the npm Electron distribution supplied by nixpkgs.

scripts/trace-daemon.mjs

@@ -28,14 +28,24 @@ const { sherpaPlatformPackageName } = await import(
   ).href
 );
 
+const traceDesktop = process.env.PASEO_TRACE_DESKTOP === "1";
+
 // Daemon entry points. Workers forked into their own Node processes have
 // independent require trees; nft does not follow fork boundaries, so trace
-// them separately.
+// them separately. The desktop derivation opts into tracing its Electron main
+// process and preloads as well.
 const entries = [
   "packages/cli/dist/index.js",
   "packages/server/dist/scripts/supervisor-entrypoint.js",
   "packages/server/dist/server/terminal/terminal-worker-process.js",
   "packages/server/dist/server/server/speech/providers/local/worker-process.js",
+  ...(traceDesktop
+    ? [
+        "packages/desktop/dist/main.js",
+        "packages/desktop/dist/preload.js",
+        "packages/desktop/dist/features/browser-keyboard/guest-preload.js",
+      ]
+    : []),
 ];
 
 // Files read at runtime via fs APIs rather than `require`. nft only
@@ -59,6 +69,16 @@ const additionalInputs = [
   // Copy the wrapper plus the host platform package explicitly.
   "node_modules/sherpa-onnx-node/**",
   `node_modules/${sherpaPlatformPackageName()}/**`,
+  ...(traceDesktop
+    ? [
+        // The unpackaged Nix launcher resolves these beside desktop/dist.
+        "packages/desktop/package.json",
+        "packages/desktop/assets/**",
+        // resolveExternalCliEntrypoint() looks up the workspace through this
+        // link at runtime; nft traces the target files but not the link.
+        "node_modules/@getpaseo/cli",
+      ]
+    : []),
 ];
 
 // Trace.
@@ -83,6 +103,9 @@ const { fileList, warnings } = await nodeFileTrace(entries, {
     // tries to walk into them via index files. Belt and suspenders.
     "**/*.test.js",
     "**/*.e2e.test.js",
+    // The Nix desktop package runs under nixpkgs' Electron. Tracing the npm
+    // package would duplicate the complete Electron distribution in $out.
+    ...(traceDesktop ? ["node_modules/electron/**"] : []),
   ],
 });