Module rule_watcher 

Hot-reload of TOML rule packs.

ProviderRegistry is constructed once at boot today; adding a new vendor TOML requires a process restart. Production deployments hate restarts, especially when the only thing that changed is data (a new [[provider]] block), not code.

HotReloadRegistry wraps an Arc<ProviderRegistry> behind an arc-swap style atomic load + a background polling task. Operators drop a new TOML into the watched directory; the background task notices the mtime change, re-loads + re-builds the registry, and atomically swaps the pointer. In-flight detects see whichever version was current at the start of their call; concurrent solves never observe a partially-loaded registry.

Pure-Rust polling watcher

No notify crate dependency — that would pull in OS-specific inotify/kqueue/ReadDirectoryChangesW bindings + their build infrastructure. A 2-second mtime poll is sufficient for the “ops drops a TOML” use case (we don’t need millisecond reactions; minutes-scale config rollouts are the norm). The poller skips when no file in the watched dir changed, so the steady-state cost is one stat() per file every 2 seconds.

What this module does NOT ship

• Schema-validation feedback. If a new TOML has bad syntax, the load fails + we log; the previously-loaded registry stays active. Operators want a validate-rules pre-flight before dropping the file in production — that’s [captchaforge cli validate-rules].
• Per-file change tracking. We re-scan the whole dir on any change; cheap because rule packs are <100KB total.

Structs

HotReloadRegistry

Hot-reloadable provider registry.