diff --git a/apps/desktop/scripts/build-harness.mjs b/apps/desktop/scripts/build-harness.mjs
index ca357bfa71..db970c175f 100644
--- a/apps/desktop/scripts/build-harness.mjs
+++ b/apps/desktop/scripts/build-harness.mjs
@@ -67,7 +67,11 @@ for (const [label, path] of [
   }
 }
 
-rmSync(out, { recursive: true, force: true })
+// Recursively removing the previous (multi-GB, symlink-heavy) harness can hit
+// ENOTEMPTY/EBUSY transiently — on Windows especially, and on macOS under load.
+// Retry so the rebuild is robust; maxRetries/retryDelay are Node's built-in
+// answer to exactly these codes.
+rmSync(out, { recursive: true, force: true, maxRetries: 10, retryDelay: 250 })
 mkdirSync(join(out, 'apps'), { recursive: true })
 mkdirSync(join(out, 'bin'), { recursive: true })
 
@@ -223,7 +227,28 @@ function pruneNodeModules(nmDir) {
       console.log(`  [exclude] ${name} — removed top-level link (${fmtSize(sz)})`)
     }
 
-    // --- 5. Drop .bin shims that pointed into the removed store entries ---
+    // --- 5. Delete the flat .pnpm/node_modules/<name> copy. cpSync dereferences
+    // links while copying, so an excluded package lands here as a REAL directory
+    // (e.g. electron → 837 MB) that steps 2–4 never touch; it was shipping anyway.
+    // This shares the same safety check in step 2 — no kept package depends on it.
+    // Probe with lstatSync (not existsSync): it inspects the link itself rather
+    // than following the target, so a dangling symlink/junction (its .pnpm store
+    // entry already removed in step 3) is still found and removed on Windows. ---
+    const flat = join(pnpmDir, 'node_modules', ...name.split('/'))
+    let flatStat
+    try {
+      flatStat = lstatSync(flat)
+    } catch {
+      flatStat = null
+    }
+    if (flatStat) {
+      const sz = flatStat.isSymbolicLink() || flatStat.isFile() ? flatStat.size : dirSize(flat)
+      rmSync(flat, { recursive: true, force: true })
+      totalFreed += sz
+      console.log(`  [exclude] ${name} — removed flat .pnpm/node_modules copy (${fmtSize(sz)})`)
+    }
+
+    // --- 6. Drop .bin shims that pointed into the removed store entries ---
     removeBinShims(join(nmDir, '.bin'), matching, pnpmDir)
   }
 
diff --git a/apps/desktop/scripts/harness-excludes.json b/apps/desktop/scripts/harness-excludes.json
index 19f29b1456..e3829f9975 100644
--- a/apps/desktop/scripts/harness-excludes.json
+++ b/apps/desktop/scripts/harness-excludes.json
@@ -58,6 +58,18 @@
     {
       "name": "@electron/universal",
       "reason": "electron-builder toolchain (group): macOS universal binaries; build-time only."
+    },
+    {
+      "name": "@electron/get",
+      "reason": "Orphan of the excluded electron toolchain: @electron/rebuild's download helper. No kept package imports it at runtime."
+    },
+    {
+      "name": "@electron/rebuild",
+      "reason": "Orphan of the excluded electron toolchain: rebuilds native addons for the Electron ABI, which this app never needs (harness runs under system-Node)."
+    },
+    {
+      "name": "@electron-internal/extract-zip",
+      "reason": "Orphan of the excluded electron-builder toolchain: internal zip extraction used only during packaging. Build-time only."
     }
   ]
 }