ci: add Python 3.14 to test matrix

[bluetoothbot]

What

Add Python 3.14 to the CI test matrix.

Why

Closes #141. CI tested only 3.11–3.13; 3.14 is now GA and the library declares python = "^3.9", so the newest interpreter went unverified on every push.

How

One line in .github/workflows/ci.yml matrix. No source changes needed — the package is already compatible.

Testing

Built a clean 3.14.5 venv and ran the suite: 8 passed, including under -W error (no DeprecationWarnings). Import smoke test passes.

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Quality Report

Changes: 1 file changed, 1 insertion(+)

Code scan: clean

Tests: passed (8 passed)

Branch hygiene: clean

Generated by Kōan

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 94.37%. Comparing base (31bd826) to head (28c4fd0).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #144   +/-   ##
=======================================
  Coverage   94.37%   94.37%           
=======================================
  Files          12       12           
  Lines         480      480           
  Branches        5        5           
=======================================
  Hits          453      453           
  Misses         26       26           
  Partials        1        1           

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