chore: sync package-lock.json version fields to 2.68.0

The lockfile was still pointing at 2.66.1 after the v2.68.0 release;
`npm install` during the audit work resynced it. No dependency graph
changes, just version-string alignment.

https://claude.ai/code/session_0174sYny3VvdwYTdCNTmY4Do

package-lock.json

@@ -1,12 +1,12 @@
 {
   "name": "gsd-pi",
-  "version": "2.66.1",
+  "version": "2.68.0",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "gsd-pi",
-      "version": "2.66.1",
+      "version": "2.68.0",
       "hasInstallScript": true,
       "license": "MIT",
       "workspaces": [
@@ -9535,7 +9535,7 @@
     },
     "packages/pi-coding-agent": {
       "name": "@gsd/pi-coding-agent",
-      "version": "2.66.1",
+      "version": "2.68.0",
       "dependencies": {
         "@mariozechner/jiti": "^2.6.2",
         "@silvia-odwyer/photon-node": "^0.3.4",