diff --git a/desktop/electron/services/notifications.ts b/desktop/electron/services/notifications.ts
index 68156ab4..e028fee6 100644
--- a/desktop/electron/services/notifications.ts
+++ b/desktop/electron/services/notifications.ts
@@ -23,6 +23,15 @@ export function validateNotificationOptions(value: unknown): value is DesktopNot
     && (record.extra === undefined || (typeof record.extra === 'object' && record.extra !== null && !Array.isArray(record.extra)))
 }
 
+// NOTE: Electron has no API to read the macOS user authorization status from the
+// main process (`systemPreferences.getNotificationSettings()` does not exist; the
+// only option is the native `macos-notification-state` module, which we avoid to
+// keep the cross-platform build dependency-free). `Notification.isSupported()`
+// reflects OS capability, NOT whether the user granted permission, so this can
+// report 'granted' even when the user denied notifications in System Settings.
+// The authoritative delivery signal is the 'failed' lifecycle event handled in
+// sendDesktopNotification(); on macOS, events only emit correctly for code-signed
+// builds (unsigned/ad-hoc builds emit 'failed').
 export function notificationPermissionState(
   NotificationClass: ElectronNotificationConstructor,
 ): NotificationPermissionState {
diff --git a/desktop/electron/services/serverRuntime.ts b/desktop/electron/services/serverRuntime.ts
index a3c1e815..b4a6475e 100644
--- a/desktop/electron/services/serverRuntime.ts
+++ b/desktop/electron/services/serverRuntime.ts
@@ -5,6 +5,7 @@ import {
   formatStartupError,
   killSidecar,
   mergeProxyEnv,
+  POWERSHELL_PATH_OVERRIDE_ENV,
   proxyUrlFromElectronProxyRules,
   pushStartupLog,
   reserveLocalPort,
@@ -12,8 +13,10 @@ import {
   SERVER_CONTROL_HOST,
   spawnSidecar,
   waitForServer,
+  windowsPowerShellOverride,
   type SidecarChild,
 } from './sidecarManager'
+import { readDesktopTerminalConfig, resolveDesktopTerminalShell } from './terminal'
 
 type ServerRuntimeOptions = {
   desktopRoot: string
@@ -157,17 +160,33 @@ export class ElectronServerRuntime {
   }
 
   private async resolveSidecarBaseEnvOnce(): Promise<NodeJS.ProcessEnv> {
-    if (!this.resolveSystemProxy) return process.env
+    if (!this.resolveSystemProxy) return this.applyPowerShellOverride(process.env)
 
     try {
       const rules = await this.resolveSystemProxy('https://auth.openai.com/')
-      return mergeProxyEnv(
+      return this.applyPowerShellOverride(mergeProxyEnv(
         process.env,
         proxyUrlFromElectronProxyRules(rules),
-      )
+      ))
     } catch (error) {
       console.error('[desktop] failed to resolve system proxy for sidecars', error)
-      return process.env
+      return this.applyPowerShellOverride(process.env)
     }
   }
+
+  // On Windows, forward the user's chosen PowerShell to the agent sidecar so its
+  // PowerShellTool honors the same shell as the UI terminal (regression from the
+  // Tauri build, where this lived in src-tauri/src/lib.rs). Best-effort: never
+  // block sidecar startup, and never override an explicitly set env var.
+  private applyPowerShellOverride(env: NodeJS.ProcessEnv): NodeJS.ProcessEnv {
+    if (process.platform !== 'win32' || env[POWERSHELL_PATH_OVERRIDE_ENV]) return env
+    try {
+      const shell = resolveDesktopTerminalShell('win32', readDesktopTerminalConfig(env))
+      const override = windowsPowerShellOverride(shell, 'win32')
+      if (override) return { ...env, [POWERSHELL_PATH_OVERRIDE_ENV]: override }
+    } catch {
+      // Misconfigured custom shell etc. — fall through to the unmodified env.
+    }
+    return env
+  }
 }
diff --git a/desktop/electron/services/sidecarManager.test.ts b/desktop/electron/services/sidecarManager.test.ts
index d8d7c3c3..6c1f5150 100644
--- a/desktop/electron/services/sidecarManager.test.ts
+++ b/desktop/electron/services/sidecarManager.test.ts
@@ -12,6 +12,7 @@ import {
   proxyUrlFromElectronProxyRules,
   pushStartupLog,
   resolveHostTriple,
+  windowsPowerShellOverride,
   type SidecarChild,
 } from './sidecarManager'
 
@@ -148,4 +149,17 @@ describe('Electron sidecar manager', () => {
     expect(spawnSyncFn).toHaveBeenCalledWith('taskkill', ['/F', '/T', '/PID', '777'], { stdio: 'ignore' })
     expect(spawnAsync).not.toHaveBeenCalled()
   })
+
+  it('forwards a PowerShell shell choice to the sidecar only on Windows', () => {
+    expect(windowsPowerShellOverride('pwsh.exe', 'win32')).toBe('pwsh.exe')
+    expect(windowsPowerShellOverride('powershell.exe', 'win32')).toBe('powershell.exe')
+    expect(windowsPowerShellOverride('C:\\tools\\PowerShell\\pwsh.exe', 'win32')).toBe('C:\\tools\\PowerShell\\pwsh.exe')
+    // non-PowerShell selections must not be reported as a PowerShell override
+    expect(windowsPowerShellOverride('cmd.exe', 'win32')).toBeNull()
+    expect(windowsPowerShellOverride('C:\\bin\\bash.exe', 'win32')).toBeNull()
+    expect(windowsPowerShellOverride(null, 'win32')).toBeNull()
+    // never applies off Windows
+    expect(windowsPowerShellOverride('pwsh', 'darwin')).toBeNull()
+    expect(windowsPowerShellOverride('powershell.exe', 'linux')).toBeNull()
+  })
 })
diff --git a/desktop/electron/services/sidecarManager.ts b/desktop/electron/services/sidecarManager.ts
index e78e63ab..3e8f9b0f 100644
--- a/desktop/electron/services/sidecarManager.ts
+++ b/desktop/electron/services/sidecarManager.ts
@@ -140,6 +140,28 @@ export function mergeProxyEnv(
   }
 }
 
+// The agent's PowerShellTool reads this env var to honor the user's chosen shell
+// (mirrors src/utils/shell/powershellDetection.ts). Without it the agent would
+// re-autodetect PowerShell instead of using the shell the user picked in the UI.
+export const POWERSHELL_PATH_OVERRIDE_ENV = 'CLAUDE_CODE_POWERSHELL_PATH'
+
+/**
+ * Map a resolved Windows shell path to a PowerShell override for the sidecar env.
+ * Returns the path only on Windows when it points at pwsh/powershell, so that a
+ * cmd.exe or non-PowerShell custom shell selection does not get misreported as a
+ * PowerShell override. Matches the consumer's isPowerShellExecutablePath check.
+ */
+export function windowsPowerShellOverride(
+  shellPath: string | null | undefined,
+  platform: NodeJS.Platform = process.platform,
+): string | null {
+  if (platform !== 'win32') return null
+  const trimmed = shellPath?.trim()
+  if (!trimmed) return null
+  const base = trimmed.split(/[\\/]/).pop()?.toLowerCase().replace(/\.exe$/, '')
+  return base === 'pwsh' || base === 'powershell' ? trimmed : null
+}
+
 export function buildSidecarEnv(baseEnv: NodeJS.ProcessEnv, h5DistDir: string): NodeJS.ProcessEnv {
   const env: NodeJS.ProcessEnv = {
     ...baseEnv,