fix: Initialize Prometheus healthy/recording metrics with current status

The `jitsi_jibri_healthy` and `jitsi_jibri_recording` Prometheus gauges
default to 0 and only update on status transitions via publishStatus().
Since Jibri starts healthy with no transition, the metrics remain at 0
even though the instance is healthy.

Seed the metrics with the current status immediately after registering
the status handler so they reflect the actual state from startup.

Fixes #590

Author: mozkomor05

src/main/kotlin/org/jitsi/jibri/Main.kt

@@ -81,6 +81,7 @@ fun main(args: Array<String>) {
     jibriStatusManager.addStatusHandler {
         jibriManager.jibriMetrics.updateStatus(it)
     }
+    jibriManager.jibriMetrics.updateStatus(jibriStatusManager.overallStatus)
     webhookSubscribers.forEach(webhookClient::addSubscriber)
     val statusUpdaterTask = TaskPools.recurringTasksPool.scheduleAtFixedRate(
         1,