chore: Bump version to 0.30.6

Updated all component versions:
- bd CLI: 0.30.5 → 0.30.6
- Plugin: 0.30.5 → 0.30.6
- MCP server: 0.30.5 → 0.30.6
- npm package: 0.30.5 → 0.30.6

Changes in this release:
- bd graph command shows dependency counts using subgraph formatting (bd-6v2)
- types.StatusPinned for persistent beads that survive cleanup

cmd/bd/info.go

@@ -287,6 +287,14 @@ type VersionChange struct {
 
 // versionChanges contains agent-actionable changes for recent versions
 var versionChanges = []VersionChange{
+	{
+		Version: "0.30.6",
+		Date:    "2025-12-18",
+		Changes: []string{
+			"bd graph command shows dependency counts using subgraph formatting (bd-6v2)",
+			"types.StatusPinned for persistent beads that survive cleanup",
+		},
+	},
 	{
 		Version: "0.30.5",
 		Date:    "2025-12-18",