chore: upgrade package dependencies

[knowbee]

Summary

• Update the project dev dependencies to current compatible versions.
• Refresh the Yarn lockfile.
• Widen the Node engine constraint to support the current local toolchain while keeping the package installable with Yarn.

Why

This keeps the package aligned with the current Vite/Vitest/TypeScript toolchain and ensures the build remains healthy after dependency upgrades.

Validation

• yarn run v1.22.22
  $ tsc && vite build
  vite v7.3.6 building client environment for production...
  transforming...
  ✓ 459 modules transformed.
  rendering chunks...

[unplugin:dts] Start generate declaration files...
computing gzip size...
dist/rwanda.js 259.38 kB │ gzip: 77.14 kB
[unplugin:dts] Declaration files built in 479ms.

dist/rwanda.umd.cjs 184.01 kB │ gzip: 58.04 kB
✓ built in 735ms
Done in 1.56s.

• yarn run v1.22.22
  $ vitest run

RUN v3.2.7 /Users/bruce/workspace/personal/packages/rwanda.worktrees/package-analysis-upgrade-build-check

✓ test/provinces.test.ts (1 test) 2ms
✓ test/districts.test.ts (4 tests) 1ms
✓ test/cells.test.ts (5 tests) 2ms
✓ test/villages.test.ts (6 tests) 4ms
✓ test/sectors.test.ts (5 tests) 8ms

Test Files 5 passed (5)
Tests 21 passed (21)
Start at 11:47:30
Duration 897ms (transform 471ms, setup 0ms, collect 3.69s, tests 16ms, environment 0ms, prepare 162ms)

Done in 1.58s.

• Both passed successfully.