🤖 fix: git polling skips fetch when lock files present

When git operations (e.g., agent tool calls) are in progress, they create
lock files in the .git directory (index.lock, shallow.lock, etc.). The
background git fetch polling would previously run regardless, potentially
causing unexpected errors or conflicts.

Now the fetch script checks for any .lock files in the .git directory
before attempting to fetch. If locks are present, it exits cleanly with
exit code 0 and the message 'SKIP: git lock files present'.

This is a non-blocking check - the polling will just try again on its
next cycle (3s later for status, exponential backoff for fetch).

_Generated with `mux`_

Author: ammar-agent

src/common/utils/git/gitStatus.ts

@@ -86,8 +86,19 @@ export function parseGitStatusScriptOutput(output: string): ParsedGitStatusOutpu
  *
  * Environment variables disable all interactive prompts (keychain, SSH, credentials).
  * Git flags optimize for speed - only fetch refs, not objects.
+ *
+ * Lock-aware: Skips fetch if any git lock files exist in the .git directory.
+ * This avoids conflicts with concurrent git operations (e.g., agent tool calls).
+ * Common lock files: index.lock, shallow.lock, refs/heads/*.lock, config.lock
  */
 export const GIT_FETCH_SCRIPT = `
+# Skip if any git lock files exist (another operation in progress)
+GIT_DIR=$(git rev-parse --git-dir 2>/dev/null) || exit 1
+if find "$GIT_DIR" -name "*.lock" -type f 2>/dev/null | grep -q .; then
+  echo "SKIP: git lock files present"
+  exit 0
+fi
+
 # Disable ALL prompts
 export GIT_TERMINAL_PROMPT=0
 export GIT_ASKPASS=echo