mssql: the query runs as a read-only login, one line, no variables; sqlcmd is installed (hq #193)

Proven on a throwaway server: as the administrator a caller's $(SQLCMDPASSWORD) returned
the sa password, and a line beginning ':!!' ran a program in the tools container. The
statement now runs as mesh_mssql_reader (CONNECT ANY DATABASE, SELECT ALL USER SECURABLES),
with substitution off (-x), after the module's own text on the first line, and a line break
is refused. go-sqlcmd v1.10.0 is installed at a pinned digest: the image never had sqlcmd,
so every mssql tool failed with spawn sqlcmd ENOENT.

modules/mssql/package.json

@@ -1,9 +1,13 @@
 {
   "name": "@novox/module-mssql",
   "version": "0.1.0",
-  "description": "mssql — provides the mesh mssql-database interface. Its client, provisioner, tools and events live here (novox/hq ADR 0039).",
+  "description": "mssql \u2014 provides the mesh mssql-database interface. Its client, provisioner, tools and events live here (novox/hq ADR 0039).",
   "type": "module",
   "private": true,
+  "scripts": {
+    "build": "tsc client.ts index.ts tools/index.ts provisioner/index.ts --module NodeNext --moduleResolution NodeNext --target ES2022 --outDir dist",
+    "test": "npm run build && node --test --experimental-strip-types 'test/*.test.ts'"
+  },
   "dependencies": {
     "@novox/mesh-sdk": "^0.1.1"
   },