feat(app): add simple rest api

[drainpixie]

Relevant issues

• feat(website): full rewrite #1437

Brief

Rewrote the web server to FastAPI and updated to proselint 0.16.0, got rid of evil Redis.

Do note, the original server used redistogo which has been shut down for years.
We also lack the traffic and necessity for a queue as of now.

Changes

• Update web dependency group to be smaller and FastAPI oriented.
• Add web dependency group to the python-env in the Nix flake.
• Get rid of Redis worker.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 92.56%. Comparing base (5b3d0bb) to head (194565e).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1463      +/-   ##
==========================================
+ Coverage   91.39%   92.56%   +1.16%     
==========================================
  Files         100      100              
  Lines        1046     1022      -24     
==========================================
- Hits          956      946      -10     
+ Misses         90       76      -14     

Flag	Coverage Δ
macos-latest	91.97% <ø> (+1.15%)	⬆️
py3.10	92.56% <ø> (+1.16%)	⬆️
py3.11	92.56% <ø> (+1.16%)	⬆️
py3.12	92.56% <ø> (+1.16%)	⬆️
py3.13	91.97% <ø> (+1.15%)	⬆️
py3.14	91.97% <ø> (+1.15%)	⬆️
ubuntu-latest	91.97% <ø> (+1.15%)	⬆️
windows-latest	92.56% <ø> (+1.16%)	⬆️

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