feat: CLI commands, always-on Unix socket, and log file tailing

[sylvesterdamgaard]

Summary

• Always-on Unix socket — daemon starts a Unix socket listener regardless of api_enabled, enabling local management (cbox-init tui, CLI commands) without exposing a TCP port
• Full CLI command suite — list, status, start, stop, restart, scale, reload-config, and reworked logs with SSE streaming (-f flag)
• API client refactoring — extracted internal/tui/client.go to internal/apiclient/ for shared CLI/TUI use
• SSE log streaming — new /api/v1/logs/stream endpoint + client for real-time log tailing
• Log file tailing — new logging.files config to tail local app log files (e.g., Laravel's storage/logs/laravel.log) through the same pipeline as stdout/stderr (JSON parsing, level detection, filtering, redaction)
• Size-based log rotation — optional rotate config per log file (max_size, max_files)

New CLI commands

cbox-init list                     # List all processes
cbox-init status nginx             # Show process details
cbox-init start horizon            # Start a process
cbox-init stop horizon             # Stop a process
cbox-init restart horizon          # Restart a process
cbox-init scale queue-default 10   # Scale to N instances
cbox-init reload-config            # Reload config from disk
cbox-init logs nginx -f            # Stream logs via SSE

Log file tailing config example

processes:
  laravel:
    command: ["php-fpm", "-F"]
    logging:
      redaction:
        enabled: true
        patterns:
          - pattern: "password=\\S+"
            replacement: "password=***"
      files:
        laravel-log:
          path: /var/www/html/storage/logs/laravel.log
          rotate:
            max_size: 50MB
            max_files: 7
          json: { enabled: true, detect_auto: true }
          min_level: info

Test plan

• All 22 test packages pass (go test ./... -count=1)
• New internal/logtail/ package: 11 tests (rotator + tailer)
• New internal/apiclient/ package: 31 tests (client + SSE stream)
• New internal/logger/subscriber_test.go: 5 broadcaster tests
• check-config validates log file tailing config correctly
• CLI --help shows all new commands
• Manual test: docker exec into container, run cbox-init tui via socket
• Manual test: cbox-init logs -f streams real-time entries