Adds a new HiLo alarm trigger type with four configurable setpoints
(LoLo / Lo / Hi / HiHi). Each setpoint carries an optional priority,
deadband (for hysteresis), and operator message. The site runtime emits
AlarmStateChanged with an AlarmLevel field so consumers can differentiate
warning vs critical bands.
Plumbing:
- new AlarmLevel enum + AlarmStateChanged.Level/Message init properties
- AlarmTriggerEditor (Blazor) gets a HiLo render with severity tinting
- AlarmTriggerConfigCodec extracted from the editor for testability
- sitestream.proto carries level + message over gRPC
- SemanticValidator enforces numeric attribute, setpoint ordering,
non-negative deadband
- on-trigger scripts get an Alarm global (Name/Level/Priority/Message)
so notification routing can branch by severity
- per-instance InstanceAlarmOverride entity + EF migration + flattening
step + CLI commands; HiLo overrides merge setpoint-by-setpoint, binary
types whole-replace
- DebugView shows a Level badge + per-band message tooltip
- App.razor auto-reloads on permanent Blazor circuit failure
- docker/regen-proto.sh automates the proto regen workflow (the linux/arm64
protoc segfault means generated files are checked in for now)
