Module watcher 

Configuration hot-reload watcher.

Responsibility

Watch a TOML config file for changes and broadcast validated new configs to subscribers. Invalid reloads are logged and rejected — the current config remains unchanged.

Guarantees

• Only validated configs are broadcast
• Invalid file edits are logged but do not disrupt the running system
• File watching is debounced to avoid rapid re-reads on multi-write editors
• Subscribers receive the new config via a broadcast channel

NOT Responsible For

• Applying the config to the running pipeline (consumers decide what to do)
• Initial config loading (that belongs to loader)

Structs

ConfigWatcher

Watches a config file for changes and broadcasts validated updates.