Add posting.enabled master switch to disable auto-posting to Matrix

Stories are still ingested, classified, and served to the web UI; only
automatic Matrix posting is gated. Command replies (!post, !petestats)
still work. Pointer-bool so an absent key defaults to posting-on.

config.example.toml

@@ -17,6 +17,7 @@ gaming = "!gamingroomid:matrix.example.org"
 lego = "!legoroomid:matrix.example.org"
 
 [posting]
+enabled = true  # master switch for auto-posting news to Matrix; false = web-only (commands still work)
 min_interval_seconds = 300
 burst_cap_count = 3
 burst_cap_window_seconds = 1800

internal/config/config.go

@@ -57,10 +57,16 @@ type MatrixConfig struct {
 }
 
 type PostingConfig struct {
-	MinIntervalSeconds    int `toml:"min_interval_seconds"`
-	BurstCapCount         int `toml:"burst_cap_count"`
-	BurstCapWindowSeconds int `toml:"burst_cap_window_seconds"`
-	DedupCooldownHours    int `toml:"dedup_cooldown_hours"`
+	// Enabled is the master switch for automatic news posting to Matrix.
+	// When false, stories are still ingested, classified, and served to the
+	// web UI, but Pete never auto-posts them to rooms. Command replies
+	// (!post, !petestats) still work. Pointer so an absent key defaults to
+	// true (posting on) rather than Go's zero-value false.
+	Enabled               *bool `toml:"enabled"`
+	MinIntervalSeconds    int   `toml:"min_interval_seconds"`
+	BurstCapCount         int   `toml:"burst_cap_count"`
+	BurstCapWindowSeconds int   `toml:"burst_cap_window_seconds"`
+	DedupCooldownHours    int   `toml:"dedup_cooldown_hours"`
 	// DailyCapTotal is the hard global cap on posts across ALL channels in a
 	// rolling 24-hour window. 0 disables the cap.
 	DailyCapTotal int              `toml:"daily_cap_total"`
@@ -198,6 +204,10 @@ func (c *Config) applyDefaults() {
 	if c.Matrix.DisplayName == "" {
 		c.Matrix.DisplayName = "Pete"
 	}
+	if c.Posting.Enabled == nil {
+		on := true
+		c.Posting.Enabled = &on
+	}
 	if c.Posting.MinIntervalSeconds == 0 {
 		c.Posting.MinIntervalSeconds = 300
 	}

main.go

@@ -174,7 +174,11 @@ func main() {
 	go queue.Start(ctx)
 	slog.Info("post queue started")
 
+	postingEnabled := *cfg.Posting.Enabled
 	roundRobinMode := cfg.Posting.RoundRobin.Enabled
+	if !postingEnabled {
+		slog.Info("automatic Matrix posting is disabled (posting.enabled=false); stories will still be ingested and served to the web UI, and !post still works")
+	}
 
 	// Pipeline callback: route the story to its direct_route channel, then
 	// either enqueue immediately or leave it for the round-robin scheduler.
@@ -188,6 +192,12 @@ func main() {
 		channel := item.DirectRoute
 		storage.MarkClassified(item.GUID, channel, "[]")
 
+		// Posting disabled: classify and keep for the web UI / manual !post,
+		// but never auto-enqueue to Matrix.
+		if !postingEnabled {
+			return
+		}
+
 		if roundRobinMode {
 			slog.Info("story routed, awaiting round-robin tick",
 				"guid", item.GUID, "source", item.Source, "channel", channel)
@@ -215,7 +225,7 @@ func main() {
 	poller.Start(ctx)
 	slog.Info("pollers started")
 
-	if roundRobinMode {
+	if postingEnabled && roundRobinMode {
 		channelNames := make([]string, 0, len(cfg.Matrix.Channels))
 		for name := range cfg.Matrix.Channels {
 			channelNames = append(channelNames, name)