Add !post command to force-publish next queued story

Typed in a configured channel room, !post pops the head of that channel's
queue and sends immediately, bypassing min-interval, burst cap, and daily
cap. Canonical-URL dedup still applies. Empty queue gets a threaded reply.

main.go

@@ -6,6 +6,7 @@ import (
 	"log/slog"
 	"os"
 	"os/signal"
+	"strings"
 	"syscall"
 	"time"
 
@@ -17,6 +18,8 @@ import (
 	"pete/internal/poster"
 	"pete/internal/scheduler"
 	"pete/internal/storage"
+
+	"maunium.net/go/mautrix/id"
 )
 
 func main() {
@@ -80,6 +83,23 @@ func main() {
 	exp := explainer.New(mx, ollamaClient)
 	poster.SetReactionCallback(exp.Handle)
 
+	// Wire !post command: force-publish next queued story for the room's channel.
+	mx.SetMessageHandler(func(channel string, roomID id.RoomID, eventID id.EventID, sender id.UserID, body string) {
+		if strings.TrimSpace(body) != "!post" {
+			return
+		}
+		slog.Info("!post requested", "channel", channel, "sender", sender)
+		if queue.ForcePost(channel) {
+			return
+		}
+		if err := mx.PostThreadedReply(channel, eventID,
+			"nothing queued for "+channel,
+			"nothing queued for <code>"+channel+"</code>",
+		); err != nil {
+			slog.Warn("!post: failed to send empty-queue reply", "err", err)
+		}
+	})
+
 	// Set up graceful shutdown
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()