fix: session cleanup memory leak in SSE error handler

Fixed session ID mismatch in error handler that prevented proper
transport cleanup on connection errors. Error handler now uses
transport.sessionId (matching storage key) instead of outer scope
sessionId variable.

Changes:
- Fixed src/index.js line 299: use transport.sessionId for cleanup
- Added src/index.js line 300: sessionActivity cleanup
- Version bump to 1.2.1 in package.json

This resolves the issue where MCP server accumulated stale sessions
after ECONNRESET errors, causing failures after ~12 requests from n8n.

Author: PhilflowIO

package.json

@@ -1,6 +1,6 @@
 {
   "name": "tsdav-mcp-server",
-  "version": "1.2.0",
+  "version": "1.2.1",
   "description": "Model Context Protocol (MCP) server for CalDAV/CardDAV/VTODO integration via tsdav - enables AI systems to manage calendars, contacts, and tasks",
   "type": "module",
   "main": "src/index.js",
@@ -13,7 +13,9 @@
     "dev": "node --watch src/index.js",
     "test": "NODE_ENV=test NODE_OPTIONS='--experimental-vm-modules' jest",
     "test:watch": "NODE_ENV=test NODE_OPTIONS='--experimental-vm-modules' jest --watch",
-    "test:coverage": "NODE_ENV=test NODE_OPTIONS='--experimental-vm-modules' jest --coverage"
+    "test:coverage": "NODE_ENV=test NODE_OPTIONS='--experimental-vm-modules' jest --coverage",
+    "test:integration": "node tests/integration/mcp-test-runner.js",
+    "test:setup-data": "node tests/integration/setup-test-data.js"
   },
   "author": "tsdav-mcp-server contributors",
   "license": "MIT",

src/index.js

@@ -296,7 +296,8 @@ app.get('/sse', authenticateBearer, async (req, res) => {
         transportSessionId: transport.sessionId,
       }, 'SSE connection error');
       clearInterval(keepAliveInterval);
-      delete transports[sessionId];
+      delete transports[transport.sessionId];
+      sessionActivity.delete(transport.sessionId);
     });
 
     res.on('finish', () => {