chore(frontend): bump to node 26

[Nixieboluo]

Use Node.js 26.3.0 as our runtime.

Also remove jsonwebtoken from our deps, in favor of the new jose based JWT helpers.

[Nixieboluo]

Let's wait for nodejs#62526.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 61.86%. Comparing base (91fa34c) to head (4961fbd).
⚠️ Report is 26 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #6896   +/-   ##
=======================================
  Coverage   61.86%   61.86%           
=======================================
  Files           8        8           
  Lines         653      653           
=======================================
  Hits          404      404           
  Misses        202      202           
  Partials       47       47           

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