fix(git): silence getWorktrees warning when directory is not a repo

`getWorktrees` logs a warn-level line every time the managed OpenCode
process or any other caller passes a directory that is not inside a
git repository. The OpenChamber desktop main.log fills with hundreds
of these "Failed to list worktrees, returning empty list: fatal: not
a git repository ..." entries over a normal session.

The empty-list fallback is already correct (worktrees are an optional
feature), but the warning is noise that hides real git failures. Use
the existing `isNotGitRepositoryError` helper to suppress the warn
specifically for the "not a git repository" case and keep the
warning for genuine failures (lock contention, permission errors,
corrupt repos, etc.).

packages/web/server/lib/git/service.js

@@ -3738,7 +3738,15 @@ export async function getWorktrees(directory) {
       path: entry.worktree,
     }));
   } catch (error) {
-    console.warn('Failed to list worktrees, returning empty list:', error?.message || error);
+    // Worktrees are an optional feature. When the caller passes a directory
+    // that is not inside any git repository (for example, the managed
+    // OpenCode's working directory or an unconfigured project path), git
+    // exits with "fatal: not a git repository ...". Treat that as an
+    // authoritative empty result so the route handler can still respond
+    // 200 [] and the desktop main.log stays free of noise.
+    if (!isNotGitRepositoryError(error)) {
+      console.warn('Failed to list worktrees, returning empty list:', error?.message || error);
+    }
     return [];
   }
 }

packages/web/server/lib/git/service.test.js

@@ -2,7 +2,7 @@ import { execFileSync } from 'node:child_process';
 import fs from 'node:fs';
 import os from 'node:os';
 import path from 'node:path';
-import { afterEach, describe, expect, it } from 'vitest';
+import { afterEach, describe, expect, it, vi } from 'vitest';
 import simpleGit from 'simple-git';
 
 import {
@@ -13,6 +13,7 @@ import {
   getBranches,
   getRangeDiff,
   getStatus,
+  getWorktrees,
   isGitRepository,
   populateWorktreeWithLockRecovery,
   removeWorktree,
@@ -460,6 +461,47 @@ describe('worktree root resolution', () => {
   });
 });
 
+// ---------------------------------------------------------------------------
+// getWorktrees
+// ---------------------------------------------------------------------------
+
+describe('getWorktrees', () => {
+  if (!canRunGit()) {
+    it.skip('git binary not available', () => {});
+    return;
+  }
+
+  const warnSpy = vi.spyOn(console, 'warn').mockImplementation(() => {});
+
+  afterEach(() => {
+    warnSpy.mockClear();
+  });
+
+  it('returns an empty list for a non-git directory without warning', async () => {
+    const nonGit = createTempDir();
+
+    const result = await getWorktrees(nonGit);
+
+    expect(result).toEqual([]);
+    expect(warnSpy).not.toHaveBeenCalled();
+  });
+
+  it('returns the worktrees for a real git repository', async () => {
+    const repo = createTempDir();
+    runGit(repo, ['init', '-b', 'main']);
+    runGit(repo, ['config', 'user.email', 'test@example.com']);
+    runGit(repo, ['config', 'user.name', 'Test User']);
+    fs.writeFileSync(path.join(repo, 'README.md'), '# Test\n');
+    runGit(repo, ['add', 'README.md']);
+    runGit(repo, ['commit', '-m', 'init']);
+
+    const result = await getWorktrees(repo);
+
+    expect(Array.isArray(result)).toBe(true);
+    expect(warnSpy).not.toHaveBeenCalled();
+  });
+});
+
 // ---------------------------------------------------------------------------
 // createWorktree
 // ---------------------------------------------------------------------------