Binary e2e tests

[gtardif]

Also fixes error handling not executing on subcommands when running docker cli plugin

Adds only a few secs to the CI tests, since it's already all compiled for go test

[docker-agent]

Code Review Summary

I've reviewed the added code in this PR and found no issues. The implementation is clean and correct.

Changes Reviewed

✅ cmd/root/root.go - New setErrorHandlingRecursive function properly wraps error handling for all subcommands and their children. The recursive implementation correctly applies error processing to the entire command tree.

✅ e2e/binary/shellout.go - Test utility functions are well-structured with proper error handling. The ExecWithContextInDir function correctly inherits environment variables as intended for test scenarios.

✅ e2e/binary/binary_test.go - Tests cover the important execution modes (CLI plugin, cagent, docker-agent) and validate both help output and error handling.

✅ Taskfile.yml - Build and test tasks are properly configured with the new test-binary task depending on deploy-local to ensure binaries are built before testing.

✅ .github/workflows/ci.yml - Workflow correctly adds task test-binary to the test step.

The PR successfully addresses the stated goal of fixing error handling for subcommands when running as a docker cli plugin.