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/marketplace.json

@@ -9,7 +9,7 @@
       "name": "beads",
       "source": "./",
       "description": "AI-supervised issue tracker for coding workflows",
-      "version": "0.30.5"
+      "version": "0.30.6"
     }
   ]
 }