chore(release): bump version to 2.6.0

Ahead of the v2.6.0 milestone merge into `main`. The bump belongs on
`v2/main` so it flows into `main` with the rest of the milestone's work —
doing it on the merge branch instead leaves `v2/main` reading a stale
version and lets the bump leak into unrelated PRs (#2010).

There is one version number in the repo; the clients carry none. No tag is
created here: the release tag points at the merge commit on `main`.

Closes #2300

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01RsmR1iQstcrEzJFmgZXGLi
Signed-off-by: cliffhall <cliff@futurescale.com>

package-lock.json

@@ -1,12 +1,12 @@
 {
   "name": "@modelcontextprotocol/inspector",
-  "version": "2.5.0",
+  "version": "2.6.0",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "@modelcontextprotocol/inspector",
-      "version": "2.5.0",
+      "version": "2.6.0",
       "hasInstallScript": true,
       "license": "MIT",
       "dependencies": {

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@modelcontextprotocol/inspector",
-  "version": "2.5.0",
+  "version": "2.6.0",
   "description": "The Model Context Protocol Inspector",
   "keywords": [
     "MCP",