fix(release): update missed version files to 0.43.0

The 0.43.0 release bump missed several files that should have been
updated by scripts/bump-version.sh:
- npm-package/package.json
- integrations/beads-mcp/pyproject.toml
- integrations/beads-mcp/src/beads_mcp/__init__.py
- .claude-plugin/plugin.json
- .claude-plugin/marketplace.json
- cmd/bd/templates/hooks/*

This caused the NPM publish to fail (could not publish 0.42.0 over itself).

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

Executed-By: beads/crew/dave
Rig: beads
Role: crew

.claude-plugin/marketplace.json

@@ -9,7 +9,7 @@
       "name": "beads",
       "source": "./",
       "description": "AI-supervised issue tracker for coding workflows",
-      "version": "0.42.0"
+      "version": "0.43.0"
     }
   ]
 }