chore!: prepare for v1.0.0 release

Bumps the application version to 1.0.0, signaling the first stable release. This version consolidates several new features and breaking API changes.

This commit also includes various code quality improvements:
- Modernizes tests to use t.Setenv for safer environment variable handling.
- Addresses various linter warnings (gosec, errcheck).
- Updates loop syntax to use Go 1.22's range-over-integer feature.

BREAKING CHANGE: The public API has been updated for consistency and to introduce new features like context support and structured logging.
- `GetSupportedFormat()` is renamed to `SupportedFormat()`.
- `GetSupportedFormats()` is renamed to `SupportedFormats()`.
- `FetchCourse()` now requires a `context.Context` parameter.
- `NewArticulateParser()` constructor signature has been updated.

internal/exporters/bench_test.go

@@ -146,7 +146,7 @@ func createBenchmarkCourse() *models.Course {
 // createLargeBenchmarkCourse creates a large course for stress testing.
 func createLargeBenchmarkCourse() *models.Course {
 	lessons := make([]models.Lesson, 50)
-	for i := 0; i < 50; i++ {
+	for i := range 50 {
 		lessons[i] = models.Lesson{
 			ID:          string(rune(i)),
 			Title:       "Lesson " + string(rune(i)),