Expose guided training exercises on the driver's mobile profile link

"Jämna varv" and "Stegträning" previously only lived on the admin
Training page. A driver's own personal mobile profile link now offers
the same self-service configure/start/stop flow already used for the
5-minute practice timer there, with live progress computed server-side
from the driver's own share token so raw lap rows and driver IDs never
reach the client.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

package-lock.json

@@ -1,12 +1,12 @@
 {
   "name": "rc-racecore",
-  "version": "1.3.0",
+  "version": "1.4.0",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "rc-racecore",
-      "version": "1.3.0",
+      "version": "1.4.0",
       "hasInstallScript": true,
       "dependencies": {
         "better-sqlite3": "^12.11.1",