v0.2 - modular setup and test suite

This release introduces a fully modular architecture for setting up and validating an OpenBSD server configured to host a Git-backed Obsidian vault.

Highlights:

Split monolithic scripts into modular components:

    setup_system.sh, setup_obsidian_git.sh, setup_github.sh

    test_system.sh, test_obsidian_git.sh, test_github.sh

New wrapper scripts:

    setup_all.sh and test_all.sh for full automation

Environment variable support preserved across all layers

Safer deployment: deploy key no longer required to be committed

Simplified maintenance and clearer separation of concerns