feat: default list_alerts to active alerts only

Change list_alerts (MCP tool) and alerts (CLI command) to show only
active (non-silenced, non-inhibited) alerts by default. Add state=all
option and --all CLI flag to show all alerts when needed.

- MCP: list_alerts with no state param now returns active alerts only
- MCP: list_alerts with state=all returns all alerts (previous default)
- CLI: alerts command defaults to active, --all shows everything
- Add tests for new default behavior and state=all option
- Update README with new CLI examples
- Bump version to 0.3.0
- Clarify version bumping rules in CLAUDE.md

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

cmd/lab-monitoring/main.go

@@ -15,7 +15,7 @@ import (
 	"git.t-juice.club/torjus/labmcp/internal/monitoring"
 )
 
-const version = "0.2.0"
+const version = "0.3.0"
 
 func main() {
 	app := &cli.App{
@@ -113,12 +113,16 @@ func alertsCommand() *cli.Command {
 		Flags: []cli.Flag{
 			&cli.StringFlag{
 				Name:  "state",
-				Usage: "Filter by state: active, suppressed, unprocessed",
+				Usage: "Filter by state: active (default), suppressed, unprocessed, all",
 			},
 			&cli.StringFlag{
 				Name:  "severity",
 				Usage: "Filter by severity label",
 			},
+			&cli.BoolFlag{
+				Name:  "all",
+				Usage: "Show all alerts including silenced and inhibited (shorthand for --state all)",
+			},
 		},
 		Action: func(c *cli.Context) error {
 			return runAlerts(c)
@@ -226,23 +230,32 @@ func runAlerts(c *cli.Context) error {
 	am := monitoring.NewAlertmanagerClient(c.String("alertmanager-url"))
 
 	filters := monitoring.AlertFilters{}
-	if state := c.String("state"); state != "" {
-		switch state {
-		case "active":
-			active := true
-			filters.Active = &active
-			silenced := false
-			filters.Silenced = &silenced
-			inhibited := false
-			filters.Inhibited = &inhibited
-		case "suppressed":
-			active := false
-			filters.Active = &active
-		case "unprocessed":
-			unprocessed := true
-			filters.Unprocessed = &unprocessed
-		}
+
+	// Determine state filter: --all flag takes precedence, then --state, then default to active
+	state := c.String("state")
+	if c.Bool("all") {
+		state = "all"
 	}
+
+	switch state {
+	case "active", "":
+		// Default to active alerts only (non-silenced, non-inhibited)
+		active := true
+		filters.Active = &active
+		silenced := false
+		filters.Silenced = &silenced
+		inhibited := false
+		filters.Inhibited = &inhibited
+	case "suppressed":
+		active := false
+		filters.Active = &active
+	case "unprocessed":
+		unprocessed := true
+		filters.Unprocessed = &unprocessed
+	case "all":
+		// No filters - return everything
+	}
+
 	if severity := c.String("severity"); severity != "" {
 		filters.Filter = append(filters.Filter, fmt.Sprintf(`severity="%s"`, severity))
 	}