Hot-reload registry built on clj-reload.

Extends tonsky/clj-reload with:
- Named component registry
- Event-driven listeners (for hive-events integration)
- Status tracking and introspection
- Cascade control
- Watcher integration with coordinated debouncing

Design: Composition over reimplementation.

Coordination-aware debouncing for hot-reload events.

Provides debouncing with claim-awareness:
- Unclaimed files: time-based debounce (coalesce rapid changes)
- Claimed files: buffer until claims released

Design: State-based debounce windows, not just time-based.

Event emission for hive-hot integration with hive-events.

Event schemas:
- [:file/changed {:file "src/foo.clj" :type :modify|:create|:delete}]
- [:hot/reload-start {}]
- [:hot/reload-success {:loaded [ns...] :unloaded [ns...] :ms N}]
- [:hot/reload-error {:failed ns :error "message"}]

Events are dispatched via hive.events/dispatch for system-wide
observability and coordination.

Schema-driven hot-reload registration — the hive-hot leg of the malli macro
layer. `reg-hot-schema` coerces + validates a component's opts against ONE
malli schema before hive-hot.core/reg-hot stores them: declare the component's
opts schema once and its guard is wired, replacing the ad-hoc :pre check with a
real value-object contract.

hive-hot does not depend on hive-spi/malli; derive/compile-op is resolved
LAZILY via a guarded requiring-resolve. When it is unresolvable (hive-spi
absent) opts pass through and reg-hot's own :pre still guards :ns —
registration never fails on a bare classpath.

FileWatcher protocol and WatchService-based implementation.

Provides file system watching for hot-reload coordination.
Uses Java WatchService for cross-platform file event detection.