don't wrap args unnecessarily

packages/cli/src/ui/components/SessionSummaryDisplay.test.tsx

@@ -181,8 +181,9 @@ describe('<SessionSummaryDisplay />', () => {
       );
       const output = lastFrame();
 
-      // PowerShell wraps strings in single quotes
-      expect(output).toContain("gemini --resume '1234-abcd-5678-efgh'");
+      // PowerShell doesn't wraps UUID in single quotes because
+      // it contains no special characters.
+      expect(output).toContain('gemini --resume 1234-abcd-5678-efgh');
       unmount();
     });
 

packages/core/src/utils/shell-utils.test.ts

@@ -418,8 +418,8 @@ describe('escapeShellArg', () => {
       });
 
       it('should escape internal double quotes by doubling them', () => {
-        const result = escapeShellArg('He said "Hello"', 'cmd');
-        expect(result).toBe('"He said ""Hello"""');
+        const result = escapeShellArg('hello "world"', 'cmd');
+        expect(result).toBe('"hello ""world"""');
       });
 
       it('should handle empty strings', () => {
@@ -429,7 +429,12 @@ describe('escapeShellArg', () => {
     });
 
     describe('when shell is PowerShell', () => {
-      it('should wrap simple arguments in single quotes', () => {
+      it('should return simple alphanumeric arguments without quotes', () => {
+        const result = escapeShellArg('my-argument-123.txt', 'powershell');
+        expect(result).toBe('my-argument-123.txt');
+      });
+
+      it('should wrap arguments with spaces in single quotes', () => {
         const result = escapeShellArg('search term', 'powershell');
         expect(result).toBe("'search term'");
       });

packages/core/src/utils/shell-utils.ts

@@ -695,9 +695,17 @@ export function escapeShellArg(arg: string, shell: ShellType): string {
 
   switch (shell) {
     case 'powershell':
-      // For PowerShell, wrap in single quotes and escape internal single quotes by doubling them.
+      // For PowerShell, avoid quoting simple alphanumeric strings (like UUIDs).
+      if (/^[a-zA-Z0-9\-_.]+$/.test(arg)) {
+        return arg;
+      }
+      // Otherwise, wrap in single quotes and escape internal single quotes by doubling them.
       return `'${arg.replace(/'/g, "''")}'`;
     case 'cmd':
+      // Avoid quoting simple strings for cmd.exe as well.
+      if (/^[a-zA-Z0-9\-_.]+$/.test(arg)) {
+        return arg;
+      }
       // Simple Windows escaping for cmd.exe: wrap in double quotes and escape inner double quotes.
       return `"${arg.replace(/"/g, '""')}"`;
     case 'bash':