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

cmd/bd/templates/hooks/post-checkout

@@ -1,6 +1,6 @@
 #!/usr/bin/env sh
 # bd-shim v1
-# bd-hooks-version: 0.42.0
+# bd-hooks-version: 0.43.0
 #
 # bd (beads) post-checkout hook - thin shim
 #

cmd/bd/templates/hooks/post-merge

@@ -1,6 +1,6 @@
 #!/usr/bin/env sh
 # bd-shim v1
-# bd-hooks-version: 0.42.0
+# bd-hooks-version: 0.43.0
 #
 # bd (beads) post-merge hook - thin shim
 #

cmd/bd/templates/hooks/pre-commit

@@ -1,6 +1,6 @@
 #!/usr/bin/env sh
 # bd-shim v1
-# bd-hooks-version: 0.42.0
+# bd-hooks-version: 0.43.0
 #
 # bd (beads) pre-commit hook - thin shim
 #

cmd/bd/templates/hooks/pre-push

@@ -1,6 +1,6 @@
 #!/usr/bin/env sh
 # bd-shim v1
-# bd-hooks-version: 0.42.0
+# bd-hooks-version: 0.43.0
 #
 # bd (beads) pre-push hook - thin shim
 #