fix: prevent orphaned installer processes from blocking retries (#790)

* fix: prevent orphaned installer processes from blocking retries

When the `timeout` command expires during Claude Code installation, it only
kills the direct child bash process, not the grandchild installer processes.
These orphaned processes continue holding a lock file, causing retry attempts
to fail with "another process is currently installing Claude".

Add `--foreground` flag to run the command in a foreground process group so
all child processes are killed on timeout. Add `--kill-after=10` to send
SIGKILL if SIGTERM doesn't terminate processes within 10 seconds.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

   Co-Authored-By: Claude <noreply@anthropic.com>

* fix: apply same timeout fix to root action.yml

🤖 Generated with [Claude Code](https://claude.com/claude-code)

   Co-Authored-By: Claude <noreply@anthropic.com>

Author: ashwin-ant

action.yml

@@ -213,7 +213,8 @@ runs:
           for attempt in 1 2 3; do
             echo "Installation attempt $attempt..."
             if command -v timeout &> /dev/null; then
-              timeout 120 bash -c "curl -fsSL https://claude.ai/install.sh | bash -s -- $CLAUDE_CODE_VERSION" && break
+              # Use --foreground to kill entire process group on timeout, --kill-after to send SIGKILL if SIGTERM fails
+              timeout --foreground --kill-after=10 120 bash -c "curl -fsSL https://claude.ai/install.sh | bash -s -- $CLAUDE_CODE_VERSION" && break
             else
               curl -fsSL https://claude.ai/install.sh | bash -s -- "$CLAUDE_CODE_VERSION" && break
             fi

base-action/action.yml

@@ -129,7 +129,8 @@ runs:
           for attempt in 1 2 3; do
             echo "Installation attempt $attempt..."
             if command -v timeout &> /dev/null; then
-              timeout 120 bash -c "curl -fsSL https://claude.ai/install.sh | bash -s -- $CLAUDE_CODE_VERSION" && break
+              # Use --foreground to kill entire process group on timeout, --kill-after to send SIGKILL if SIGTERM fails
+              timeout --foreground --kill-after=10 120 bash -c "curl -fsSL https://claude.ai/install.sh | bash -s -- $CLAUDE_CODE_VERSION" && break
             else
               curl -fsSL https://claude.ai/install.sh | bash -s -- "$CLAUDE_CODE_VERSION" && break
             fi