feat: initial Beta 1 release

- soju raw connector with event playback and CHATHISTORY fallback
- SQLite store with msgid de-dup and retention job
- Mentions + Pushover + tuning; structured JSON logs
- Summaries: concise, link-following, multi-line grouping
- HTTP: /healthz, /ready, /tail, /trigger, /metrics
- Docker: distroless, healthcheck, version metadata
- Docs: README, CHANGELOG, compose

internal/scheduler/scheduler.go

@@ -0,0 +1,31 @@
+package scheduler
+
+import (
+    "context"
+    "log"
+    "time"
+
+    "github.com/robfig/cron/v3"
+)
+
+// Start runs the cron scheduler until ctx is done.
+func Start(ctx context.Context, spec string, job func(now time.Time), logger *log.Logger) error {
+    c := cron.New(cron.WithParser(cron.NewParser(cron.SecondOptional|cron.Minute|cron.Hour|cron.Dom|cron.Month|cron.Dow|cron.Descriptor)))
+    _, err := c.AddFunc(spec, func() {
+        job(time.Now())
+    })
+    if err != nil {
+        return err
+    }
+    if logger != nil {
+        logger.Printf("scheduler started: %s", spec)
+    }
+    c.Start()
+    go func() {
+        <-ctx.Done()
+        c.Stop()
+    }()
+    return nil
+}
+
+