chore: fix tmp path traversal vulnerability and update test count

Run npm audit fix to resolve CVE in tmp (path traversal via
unsanitized prefix/postfix). Remaining 3 vulnerabilities are in
mocha, locked by vscode-extension-tester (dev-only, not shipped).

Update binaryDiscovery test count in AGENTS.md from 10 to 11.

Signed-off-by: Sebastien Tardif <sebtardif@ncf.ca>

Author: SebTardif

AGENTS.md

@@ -45,7 +45,7 @@ test/
   unit/                  Unit tests (node:test, dependency-injected, no VS Code API)
     batchApply.test.ts   Batch template and operation count parsing (10 tests)
     binary.test.ts       Binary discovery, managed install, compatibility, workspace env (38 tests)
-    binaryDiscovery.test.ts  Real executable discovery on PATH (10 tests)
+    binaryDiscovery.test.ts  Real executable discovery on PATH (11 tests)
     initializeProject.test.ts  Status display, agents file classification, formatError (18 tests)
     managedLifecycle.test.ts   Managed install with real file I/O (12 tests)
     mcpConfig.test.ts    MCP config with real temp directories (9 tests)