SD-M4: mesh-contracts declares its Go and TypeScript packages, series 0.1, generated from its definitions (design 26)

Each package carries the contracts marker generated-from naming the module's root, where seats/, parts/ and format/
are. No merge-check.sh: the checker runs every repository's tests by Go's convention (ADR 0529).

Claude-Session: https://claude.ai/code/session_01JG73KJNrH5EgFXMKKYSrig

module.json

@@ -0,0 +1,12 @@
+{
+  "module": "mesh-contracts",
+  "version": "1",
+  "slug": "contracts",
+  "build": {
+    "artifacts": [
+      { "name": "go", "kind": "package", "language": "go", "paths": ["go"], "series": "0.1", "generated-from": "." },
+      { "name": "lib", "kind": "package", "language": "typescript", "paths": ["ts"], "series": "0.1", "generated-from": "." }
+    ]
+  },
+  "resources": []
+}