v0.2.0

What's New

• feat(scheduler): interval task scheduler
• feat(signals): shutdown flag and signal kinds
• feat(proc-table): process table TUI widget
• feat(env-manager): environment variable manager
• feat(metrics): atomic counter/gauge registry
• feat(health): health check aggregator
• feat(log-sink): structured log sink with ring buffer
• feat(config): key=value config loader
• feat(watchdog): process watchdog with restart cap
• feat(plugins): executable plugin registry v1
• fix(watchdog): clone name before move in register()

137 unit tests passing.