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/docker.v

@@ -0,0 +1,68 @@
+module sources
+
+import x.json2 as json
+
+pub fn transform_docker_event(raw string, source DockerSource, host string) ?Event {
+	doc := json.decode[json.Any](raw, json.DecoderOptions{}) or { return none }
+	obj := doc.as_map()
+
+	event_type := get_string(obj, 'status')
+	actor := obj['Actor'] or { json.Any(map[string]json.Any{}) }.as_map()
+	attrs := actor['Attributes'] or { json.Any(map[string]json.Any{}) }.as_map()
+
+	container_name := get_string(attrs, 'name')
+	image := get_string(attrs, 'image')
+	exit_code := get_string(attrs, 'exitCode')
+
+	priority := source.priority_map[event_type] or { 0 }
+
+	mut tags := source.tags.clone()
+	if event_type == 'oom' && 'skull' !in tags {
+		tags << 'skull'
+	}
+
+	if source.template != '' {
+		vars := {
+			'container_name': container_name
+			'status':         event_type
+			'image':          image
+			'exit_code':      exit_code
+			'host':           host
+		}
+		return Event{
+			source:   'docker'
+			name:     source.name
+			topic:    source.topic
+			priority: priority
+			tags:     tags
+			message:  render_source_template(source.template, vars)
+			raw:      raw
+		}
+	}
+
+	emoji := match event_type {
+		'die' { '💀' }
+		'oom' { '☠️' }
+		'health_status' { '💓' }
+		else { '🐳' }
+	}
+
+	mut message := '${emoji} ${container_name} → ${event_type}'
+	if image != '' {
+		message += '\nImage: ${image}'
+	}
+	if exit_code != '' {
+		message += '\nExit code: ${exit_code}'
+	}
+	message += '\nHost: ${host}'
+
+	return Event{
+		source:   'docker'
+		name:     source.name
+		topic:    source.topic
+		priority: priority
+		tags:     tags
+		message:  message
+		raw:      raw
+	}
+}