Initial commit: waste-go skeleton

Ed25519/X25519/ChaCha20-Poly1305 crypto, peer handshake, mesh state,
IPC server, relay server, and NAT stub. Builds clean on Go 1.22+.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

.vscode/extensions.json

@@ -0,0 +1,7 @@
+{
+    "recommendations": [
+        "golang.go",
+        "usernamehw.errorlens",
+        "streetsidesoftware.code-spell-checker"
+    ]
+}