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

.claude-plugin/plugin.json

@@ -1,7 +1,7 @@
 {
   "name": "beads",
   "description": "AI-supervised issue tracker for coding workflows. Manage tasks, discover work, and maintain context with simple CLI commands.",
-  "version": "0.30.5",
+  "version": "0.30.6",
   "author": {
     "name": "Steve Yegge",
     "url": "https://github.com/steveyegge"