Dashboard: a grid of widgets, what fires, what is up, and the stream

DashboardGrid lays widgets on columns: a tile's strip drags it and its
corner resizes it a cell at a time, others move down and rise to fill
gaps, a focused tile steps with the arrows, and under the theme's
stack_below width the tiles stand in one column. DashboardCard frames a
widget. AlertList acknowledges a firing alert from its row and opens
one on Enter; IncidentCard shows an incident's gravity, phase and
updates. UptimeBar, ServiceStatus and HealthCheck show what is up, a
check's detail wrapping under its name when narrow. EventStream keeps
kinds and holds the list while new events count up.
RefreshIntervalSelector and DashboardFilterBar set the window, the
filters and the refresh. StatCard, MetricsChart, ResourceGauge,
LogStream, TraceWaterfall, SystemMonitor, ProcessTable and NetworkGraph
point to their homes; the maps wait for T41.

src/lib.rs

@@ -7,6 +7,7 @@ pub mod canvas;
 pub mod charts;
 pub mod chat;
 pub mod collab;
+pub mod dashboard;
 pub mod data_display;
 pub mod debug;
 pub mod devtools;