Fix critical bug: arcvMinimum polynomial constant was 7.1651 (wrong)
instead of 11.8371 (Odeh 2006) in getMoonVisibilityEstimate. Now
imports the canonical arcvMinimum() from visibility module.
Deduplicate shared code across modules:
- arcvMinimum polynomial: single source in visibility/index.ts
- dot/norm vector helpers: use vdot/vnorm from math/index.ts
- DEG constant: use DEG2RAD from math/index.ts
- jdToJSDate: use jdToDate from time/index.ts
Add input validation to all public API functions (lat/lon range,
valid Date instances). Add ESLint + Prettier with TypeScript support.
Convert tests to node:test runner. Fix package.json exports to use
nested types-first format. Pin devDependencies to caret ranges.
Add noImplicitReturns and noFallthroughCasesInSwitch to tsconfig.
Replace .markdownlint.json with .vscode/settings.json. Update CI
workflow with lint job. Expand .gitignore coverage.
