style(desktop): keep PM source-check bridge lint clean

apps/desktop/electron/updater/checkout-legacy.test.ts

@@ -115,6 +115,7 @@ it.skipIf(process.platform !== 'win32')(
         hermesHome: home,
         channel: 'stable' as const
       }
+
       await expect(readSourceUpdate(probe)).resolves.toMatchObject({ supported: true, channel: 'stable', behind: null })
       await expect(readSourceUpdate({ ...probe, branch: 'main&echo INJECTED' })).rejects.toThrow(
         'unsafe Windows command argument'

apps/desktop/electron/updater/checkout-source.ts

@@ -46,6 +46,7 @@ export async function readSourceUpdate(probe: SourceUpdateProbe): Promise<Source
   // The install launcher boots PM's committed Python and dependency generation.
   // A PATH Python can import this checkout yet lack its selected dependencies.
   const managed = existsSync(path.join(probe.updateRoot, 'pm'))
+
   const launcher = managed
     ? resolveInstallationLauncher(probe.updateRoot, process.platform === 'win32', probe.hermesHome)
     : null
@@ -79,13 +80,16 @@ export async function readSourceUpdate(probe: SourceUpdateProbe): Promise<Source
     ...(probe.cachePath ? ['--cache-path', probe.cachePath] : []),
     ...(probe.branchConfigPath ? ['--branch-config-path', probe.branchConfigPath] : [])
   ]
+
   const command: string = (managed ? launcher : probe.python)!
   const viaCmd: boolean = process.platform === 'win32' && /\.cmd$/i.test(command)
+
   // Node refuses direct .cmd execFile; shell:true interpolates untrusted branch
   // and path arguments. Keep cmd.exe's one unavoidable parse fail-closed.
   if (viaCmd && [command, ...args].some((value: string): boolean => /["%&|<>^\r\n]/.test(value))) {
     throw new Error('The source check contains an unsafe Windows command argument.')
   }
+
   const result: { stdout: string; stderr: string } = await execute(
     viaCmd ? (process.env.ComSpec ?? 'cmd.exe') : command,
     viaCmd