feat(shared-vault-sync): add commit-driven auto-push script

push-shared-vault.sh pushes the shared vault only when the worktree is clean
and the local branch is ahead of origin (fetch first); never rebases,
force-pushes, or resolves conflicts. Ships with launchd setup docs. Bump 0.1.2.

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

.claude-plugin/marketplace.json

@@ -18,7 +18,7 @@
       "name": "shared-vault-sync",
       "source": "./plugins/shared-vault-sync",
       "description": "Safely pulls the shared vault at session start.",
-      "version": "0.1.1"
+      "version": "0.1.2"
     }
   ]
 }