build: run unit tests in prepublishOnly

prepublishOnly only typechecked and bundled, so a compiling but failing
change could reach npm. Insert `vitest run` (unit only, no Docker) before
the bundle step in both packages, gating publish on a green unit suite.

packages/dbmole-mcp/package.json

@@ -35,7 +35,7 @@
         "typecheck": "tsc --noEmit",
         "test:unit": "vitest run",
         "coverage": "vitest run --coverage",
-        "prepublishOnly": "tsc --noEmit && tsup"
+        "prepublishOnly": "tsc --noEmit && vitest run && tsup"
     },
     "dependencies": {
         "@modelcontextprotocol/sdk": "^1.29.0",

packages/esmole-mcp/package.json

@@ -17,7 +17,7 @@
         "typecheck": "tsc --noEmit",
         "test:unit": "vitest run",
         "coverage": "vitest run --coverage",
-        "prepublishOnly": "tsc --noEmit && tsup"
+        "prepublishOnly": "tsc --noEmit && vitest run && tsup"
     },
     "dependencies": {
         "@modelcontextprotocol/sdk": "^1.29.0",