Add config validation and dashboard

Add YAML config loading with validation, env overrides for secrets, and
a web dashboard exposing health, stats, and recent events.

sources/uptime_kuma.v

@@ -0,0 +1,53 @@
+module sources
+
+import x.json2 as json
+
+pub fn transform_uptime_kuma(raw string, source UptimeKumaSource) ?Event {
+	doc := json.decode[json.Any](raw, json.DecoderOptions{}) or { return none }
+	obj := doc.as_map()
+
+	monitor := get_string(obj, 'monitor.name')
+	status := get_string(obj, 'heartbeat.status')
+	msg := get_string(obj, 'heartbeat.msg')
+	ping := get_string(obj, 'heartbeat.ping')
+	time_str := get_string(obj, 'heartbeat.time')
+
+	state_cfg := source.state_map[status] or { UptimeKumaState{} }
+	priority := state_cfg.priority
+	mut tags := state_cfg.tags.clone()
+
+	if source.tags.len > 0 && tags.len == 0 {
+		tags << source.tags
+	}
+
+	emoji := if status == 'up' { '✅' } else { '🚨' }
+	mut message := ''
+	if source.template != '' {
+		vars := {
+			'monitor': monitor
+			'status':  status
+			'msg':     msg
+			'ping':    ping
+			'time':    time_str
+		}
+		message = render_source_template(source.template, vars)
+	} else {
+		message = '${emoji} ${monitor} is ${status.to_upper()}'
+		if msg != '' {
+			message += ' — ${msg}'
+		}
+		if time_str != '' {
+			message += ' — ${time_str}'
+		}
+	}
+
+	return Event{
+		source:   'uptime_kuma'
+		name:     source.name
+		topic:    source.topic
+		priority: priority
+		tags:     tags
+		message:  message
+		raw:      raw
+	}
+}