Release v2.9: Auto-Update Blocklist & Log Alignment

This release introduces a container/image auto-update blocklist, aligns logging formatting consistency, renames the legacy cron log file, and introduces configuration-driven log paths.

Key Enhancements:

• Auto-Update Blocklist (EXCLUDE_CONTAINERS): Added the ability to exclude specific containers or images from automated updates using a comma-separated list of exact names or glob patterns (e.g. db_*, node:*). This is commented out by default in the configuration file.
• Smart Image Pull Skipping: If all containers running a specific image are on the blocklist, NeXdocMan will skip pulling that image entirely to conserve system bandwidth.
• Renamed Cron Log: Legacy cron.log is renamed to nexdocman_cron.log to match standard naming.
• Config-driven Log Paths: Added LOG_FILE and CRON_LOG_FILE parameters to nexdocman.cfg to make all log locations customizable.
• Log Migration: Upgrading to v2.9 automatically migrates old /var/log/NeXdocMan/cron.log entries to nexdocman_cron.log.bak to preserve your history.
• Command Output Formatting: Captured the output of container recreation tasks (docker compose up -d) to ensure log entries consistently have timestamps and prefixes.
• Failed Command Logging: Enhanced run_command to print stdout/stderr of failed commands at [ERROR] log level for easier auditing.
• Log Pruning: Extended chronological log pruning to apply to both operational and cron log files.