fix: silence stderr on best-effort package-manager probes (#491)

When bun is on PATH but its global directory was never initialized
(no `bun add -g` ever run), launching the config TUI prints
`error: No package.json was found for directory "~/.bun/install/global"`
into the terminal. The TUI probes `bun pm bin -g` (and `where`/`which`,
`npm prefix -g`, `npm root -g`) via execFileSync without an stdio
option, so the child's stderr is inherited by the parent terminal even
though the thrown error itself is caught and treated as "not found".

Add stdio: ['ignore', 'pipe', 'ignore'] to these best-effort probes
(stdout stays piped for the return value), matching the pattern already
used elsewhere in the codebase. Adds regression tests asserting every
probe call suppresses stderr and that a throwing bun probe degrades
gracefully.

Co-authored-by: Claude Fable 5 <noreply@anthropic.com>

Author: huangguang1999

src/utils/__tests__/global-command-resolution.test.ts

@@ -71,6 +71,32 @@ describe('global command resolution', () => {
         ]);
     });
 
+    it('silences child stderr on best-effort probes so failures cannot leak to the terminal', () => {
+        const execFileSyncSpy = mockExecFileSync({
+            'which -a ccstatusline': '/home/alice/.bun/bin/ccstatusline\n',
+            'bun pm bin -g': '/home/alice/.bun/bin\n'
+        });
+
+        inspectGlobalCommandResolution('bun', { platform: 'linux' });
+
+        expect(execFileSyncSpy).toHaveBeenCalled();
+        for (const call of execFileSyncSpy.mock.calls) {
+            const options = call[2] as { stdio?: string[] };
+            expect(options.stdio).toEqual(['ignore', 'pipe', 'ignore']);
+        }
+    });
+
+    it('treats a probe that throws with stderr output as not found without surfacing an error', () => {
+        vi.spyOn(childProcess, 'execFileSync').mockImplementation(() => {
+            throw new Error('error: No package.json was found for directory "C:\\Users\\alice\\.bun\\install\\global"');
+        });
+
+        const resolution = inspectGlobalCommandResolution('bun', { platform: 'win32' });
+
+        expect(resolution.resolvedPaths).toEqual([]);
+        expect(resolution.expectedBinDir).toBeNull();
+    });
+
     it('warns when multiple PATH directories contain ccstatusline', () => {
         mockExecFileSync({
             'which -a ccstatusline': '/home/alice/.bun/bin/ccstatusline\n/usr/local/bin/ccstatusline\n',

src/utils/global-command-resolution.ts

@@ -55,12 +55,14 @@ export function getCommandResolutionPaths(
             ? execFileSync('where', [command], {
                 encoding: 'utf-8',
                 timeout: COMMAND_LOOKUP_TIMEOUT_MS,
-                windowsHide: true
+                windowsHide: true,
+                stdio: ['ignore', 'pipe', 'ignore']
             })
             : execFileSync('which', ['-a', command], {
                 encoding: 'utf-8',
                 timeout: COMMAND_LOOKUP_TIMEOUT_MS,
-                windowsHide: true
+                windowsHide: true,
+                stdio: ['ignore', 'pipe', 'ignore']
             });
 
         return splitCommandOutput(output);
@@ -76,6 +78,7 @@ function getNpmGlobalBinDir(platform: NodeJS.Platform): string | null {
             encoding: 'utf-8',
             timeout: COMMAND_LOOKUP_TIMEOUT_MS,
             windowsHide: true,
+            stdio: ['ignore', 'pipe', 'ignore'],
             ...getPackageManagerShellOptions(executable, platform)
         }).trim();
 
@@ -93,10 +96,14 @@ function getNpmGlobalBinDir(platform: NodeJS.Platform): string | null {
 
 function getBunGlobalBinDir(): string | null {
     try {
+        // bun writes an error to stderr when its global dir was never
+        // initialized (no `bun add -g` ever run); silence it so best-effort
+        // probing cannot leak into the TUI terminal.
         const binDir = execFileSync('bun', ['pm', 'bin', '-g'], {
             encoding: 'utf-8',
             timeout: COMMAND_LOOKUP_TIMEOUT_MS,
-            windowsHide: true
+            windowsHide: true,
+            stdio: ['ignore', 'pipe', 'ignore']
         }).trim();
 
         return binDir || null;

src/utils/global-package-manager.ts

@@ -183,6 +183,7 @@ function getNpmGlobalPackageVersion(platform: NodeJS.Platform): string | null {
             encoding: 'utf-8',
             timeout: VERSION_LOOKUP_TIMEOUT_MS,
             windowsHide: true,
+            stdio: ['ignore', 'pipe', 'ignore'],
             ...getPackageManagerShellOptions(executable, platform)
         }).trim();