fix: derive SERVER_VERSION from package.json

dbmole reported a hardcoded SERVER_VERSION of 0.1.0 while the package was
already published as 0.1.1: the constant had drifted because a bump has to
touch two places. Both servers now read the version from package.json
(resolveJsonModule + a JSON import attribute), so a release updates one
place and the reported version can no longer fall behind.

Add a dbmole guard test that add_connection publishes a non-empty
inputSchema with the expected required fields, mirroring esmole, so a future
`.superRefine` on the schema cannot silently empty it.

tsconfig.base.json

@@ -3,6 +3,7 @@
         "target": "ES2022",
         "module": "NodeNext",
         "moduleResolution": "NodeNext",
+        "resolveJsonModule": true,
         "strict": true,
         "skipLibCheck": true,
         "esModuleInterop": true,