diff --git a/config/packaged-runtime-node-modules.cjs b/config/packaged-runtime-node-modules.cjs
index 30f0e999c3f..1eca37b7c05 100644
--- a/config/packaged-runtime-node-modules.cjs
+++ b/config/packaged-runtime-node-modules.cjs
@@ -439,24 +439,22 @@ function prunePackagedParcelWatcher(resourcesDir, electronPlatformName, electron
   }
 }
 
-function prunePackagedRuntimeTypeDeclarations(resourcesDir) {
-  const nodeModulesDir = join(resourcesDir, 'node_modules')
-  if (!existsSync(nodeModulesDir)) {
-    return
-  }
-  pruneMatchingFiles(nodeModulesDir, (filename) => TYPE_DECLARATION_ARTIFACT_RE.test(filename))
+// Why type declarations: they are compile-time only; the packaged app never resolves them.
+// Why source maps: they embed the original sources (megabytes for @linear/sdk alone) and
+// nothing in the packaged app turns on Node's source-map support, so they are never read.
+// Orca's own main-process maps live outside node_modules and ship as a separate release artifact.
+function isPrunableTypeOrSourceMapArtifact(filename) {
+  return TYPE_DECLARATION_ARTIFACT_RE.test(filename) || JS_SOURCE_MAP_ARTIFACT_RE.test(filename)
 }
 
-function prunePackagedRuntimeSourceMaps(resourcesDir) {
-  // Why: dependency source maps embed the original sources (megabytes for
-  // @linear/sdk alone), and nothing in the packaged app turns on Node's
-  // source-map support, so they are never read. Orca's own main-process maps
-  // live outside node_modules and ship as a separate release artifact.
+// Why one walk: pruneMatchingFiles only ever deletes files, so passes over the same tree
+// commute — a second recursive traversal costs seconds for no extra deletions.
+function prunePackagedRuntimeTypeAndSourceMapArtifacts(resourcesDir) {
   const nodeModulesDir = join(resourcesDir, 'node_modules')
   if (!existsSync(nodeModulesDir)) {
     return
   }
-  pruneMatchingFiles(nodeModulesDir, (filename) => JS_SOURCE_MAP_ARTIFACT_RE.test(filename))
+  pruneMatchingFiles(nodeModulesDir, isPrunableTypeOrSourceMapArtifact)
 }
 
 function prunePackagedSherpaOnnx(resourcesDir, electronPlatformName) {
@@ -494,10 +492,10 @@ function prunePackagedRuntimeNodeModules(resourcesDir, electronPlatformName, ele
   const architecture = normalizeElectronArchitecture(electronArch)
   prunePackagedNodePty(resourcesDir, electronPlatformName, architecture)
   prunePackagedParcelWatcher(resourcesDir, electronPlatformName, architecture)
-  prunePackagedRuntimeTypeDeclarations(resourcesDir)
-  prunePackagedRuntimeSourceMaps(resourcesDir)
-  prunePackagedSherpaOnnx(resourcesDir, electronPlatformName)
+  // Why before the filename walk: zod/src is deleted wholesale, so walking it first is wasted work.
   prunePackagedZodSources(resourcesDir)
+  prunePackagedRuntimeTypeAndSourceMapArtifacts(resourcesDir)
+  prunePackagedSherpaOnnx(resourcesDir, electronPlatformName)
 }
 
 function pruneMatchingFiles(directory, shouldPrune) {
@@ -520,9 +518,8 @@ module.exports = {
   prunePackagedNodePty,
   prunePackagedParcelWatcher,
   prunePackagedRuntimeNodeModules,
-  prunePackagedRuntimeSourceMaps,
+  prunePackagedRuntimeTypeAndSourceMapArtifacts,
   prunePackagedSherpaOnnx,
-  prunePackagedRuntimeTypeDeclarations,
   prunePackagedZodSources,
   verifyPackagedMainRuntimeDeps
 }
diff --git a/config/scripts/electron-builder-config.test.mjs b/config/scripts/electron-builder-config.test.mjs
index 152061b432d..347cae8fcfc 100644
--- a/config/scripts/electron-builder-config.test.mjs
+++ b/config/scripts/electron-builder-config.test.mjs
@@ -17,7 +17,7 @@ const {
   prunePackagedNodePty,
   prunePackagedParcelWatcher,
   prunePackagedSherpaOnnx,
-  prunePackagedRuntimeTypeDeclarations,
+  prunePackagedRuntimeTypeAndSourceMapArtifacts,
   prunePackagedZodSources,
   verifyPackagedMainRuntimeDeps
 } = require('../packaged-runtime-node-modules.cjs')
@@ -534,9 +534,11 @@ describe('electron-builder config', () => {
       await writeFile(join(packageDir, 'dist', 'index.cjs'), 'module.exports = {}', 'utf8')
       await writeFile(join(packageDir, 'dist', 'index.d.ts'), 'export type Value = string', 'utf8')
       await writeFile(join(packageDir, 'dist', 'index.d.cts'), 'export type Value = string', 'utf8')
+      await writeFile(join(packageDir, 'dist', 'index.d.mts'), 'export type Value = string', 'utf8')
+      await writeFile(join(packageDir, 'dist', 'index.d.cts.map'), '{}', 'utf8')
       await writeFile(join(packageDir, 'dist', 'index.d.mts.map'), '{}', 'utf8')
 
-      prunePackagedRuntimeTypeDeclarations(resourcesDir)
+      prunePackagedRuntimeTypeAndSourceMapArtifacts(resourcesDir)
 
       await expect(readdir(join(packageDir, 'dist'))).resolves.toEqual(['index.cjs'])
     } finally {
diff --git a/config/scripts/packaged-source-map-prune.test.mjs b/config/scripts/packaged-source-map-prune.test.mjs
index 0650e03ca56..ac21d374ae6 100644
--- a/config/scripts/packaged-source-map-prune.test.mjs
+++ b/config/scripts/packaged-source-map-prune.test.mjs
@@ -6,7 +6,7 @@ import { describe, expect, it } from 'vitest'
 
 const require = createRequire(import.meta.url)
 const {
-  prunePackagedRuntimeSourceMaps,
+  prunePackagedRuntimeTypeAndSourceMapArtifacts,
   prunePackagedRuntimeNodeModules
 } = require('../packaged-runtime-node-modules.cjs')
 
@@ -54,14 +54,14 @@ async function createPackagedNodeModulesFixture(resourcesDir) {
   return { packageDir, distDir, webhooksDir, updaterDir, jsYamlDir, nodePtyDir }
 }
 
-describe('packaged runtime source-map pruning', () => {
+describe('packaged runtime type-declaration and source-map pruning', () => {
   it('removes @linear/sdk source maps while preserving runtime files and non-JS maps', async () => {
     const resourcesDir = await mkdtemp(join(tmpdir(), 'orca-source-map-prune-'))
     try {
       const { packageDir, distDir, webhooksDir } =
         await createPackagedNodeModulesFixture(resourcesDir)
 
-      prunePackagedRuntimeSourceMaps(resourcesDir)
+      prunePackagedRuntimeTypeAndSourceMapArtifacts(resourcesDir)
 
       await expect(readdir(distDir).then((entries) => entries.sort())).resolves.toEqual([
         'index.cjs',
@@ -91,7 +91,7 @@ describe('packaged runtime source-map pruning', () => {
     try {
       const { jsYamlDir, nodePtyDir } = await createPackagedNodeModulesFixture(resourcesDir)
 
-      prunePackagedRuntimeSourceMaps(resourcesDir)
+      prunePackagedRuntimeTypeAndSourceMapArtifacts(resourcesDir)
 
       await expect(readdir(jsYamlDir)).resolves.toEqual(['js-yaml.min.js'])
       await expect(readdir(nodePtyDir)).resolves.toEqual(['index.js'])
@@ -100,25 +100,20 @@ describe('packaged runtime source-map pruning', () => {
     }
   })
 
-  it('leaves declaration-map cleanup to the type-declaration prune', async () => {
+  it('removes type declarations and declaration maps in the same walk', async () => {
     const resourcesDir = await mkdtemp(join(tmpdir(), 'orca-source-map-prune-dts-'))
     try {
       const { updaterDir } = await createPackagedNodeModulesFixture(resourcesDir)
 
-      prunePackagedRuntimeSourceMaps(resourcesDir)
+      prunePackagedRuntimeTypeAndSourceMapArtifacts(resourcesDir)
 
-      // Why: the two predicates are disjoint -- `.d.ts.map` never ends in `.js.map`.
-      await expect(readdir(updaterDir).then((entries) => entries.sort())).resolves.toEqual([
-        'main.d.ts',
-        'main.d.ts.map',
-        'main.js'
-      ])
+      await expect(readdir(updaterDir)).resolves.toEqual(['main.js'])
     } finally {
       await rm(resourcesDir, { recursive: true, force: true })
     }
   })
 
-  it('runs the source-map prune through aggregate runtime cleanup', async () => {
+  it('runs the artifact prune through aggregate runtime cleanup', async () => {
     const resourcesDir = await mkdtemp(join(tmpdir(), 'orca-source-map-aggregate-prune-'))
     try {
       const { distDir, updaterDir, packageDir } =