Update for Python 3.14, Django 6.0, and modern ruff configuration

[rh0dium]

Summary

• Update requires-python to >=3.12
• Add Python 3.14 and Django 6.0 to classifiers
• Update Django dependency to >=5.2
• Modernize ruff configuration with full settings
• Update pre-commit hooks to latest versions (hooks v5.0.0, ruff v0.8.3)
• Update GitHub CI matrix to test Python 3.12/3.13/3.14 and Django 5.2/6.0
• Mark Django 6.0 and Python 3.14 tests as continue-on-error for now

Test plan

• Local tests pass
• CI tests pass for Python 3.12/3.13 with Django 5.2
• CI shows Django 6.0/Python 3.14 tests as informational

🤖 Generated with Claude Code

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 75.69%. Comparing base (b2d0c14) to head (804e7c8).
⚠️ Report is 1 commits behind head on master.

Additional details and impacted files

@@           Coverage Diff           @@
##           master      #14   +/-   ##
=======================================
  Coverage   75.69%   75.69%           
=======================================
  Files           7        7           
  Lines         646      646           
  Branches       87       87           
=======================================
  Hits          489      489           
  Misses        113      113           
  Partials       44       44           

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.