release: 0.1.6 — relay notifications/progress to MCP client

Long-running upstream skills emit MCP notifications/progress on the SSE
stream. Without forwarding, the gateway swallows them and the MCP
client (Claude Code, Cursor) aborts the tools/call on its idle timer
after ~60s — even though the HTTP stream stays warm.

Gateway now passes the SDK's extra.sendNotification through to
UpstreamAgent.callTool. Any non-response frame with a method but no id
becomes a notification on the client side. Each tools/call carries a
progressToken (client-supplied or request-id fallback) so the client
can correlate.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

package-lock.json

@@ -1,12 +1,12 @@
 {
   "name": "a2amcp",
-  "version": "0.1.5",
+  "version": "0.1.6",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "a2amcp",
-      "version": "0.1.5",
+      "version": "0.1.6",
       "license": "Apache-2.0",
       "dependencies": {
         "@modelcontextprotocol/sdk": "^1.0.4",