Increases the test coverage of the project from 85.5% to 89.2%.
- Adds tests for the `IsHashAlgo` function and PGP functions in `pkg/crypt`.
- Adds tests for the `main` function and command handlers in `cmd/trix`.
- Improves the overall test coverage of the `cmd/trix` package from 26.0% to 67.7%.
- Improves the overall test coverage of the `pkg/crypt` package from 78.2% to 96.2%.
Adds `go vet` to the test procedures in both the local `Taskfile.yml` and the GitHub Actions workflow.
Also includes the following changes:
- Refactors the `trix` CLI to use the `cobra` library to improve testability.
- Adds comprehensive tests for the `trix` CLI, achieving 100% test coverage.
- Fixes a closure bug in the sigil command creation loop.
- Refactors the CLI to use Cobra's I/O writers, making the output testable.
