Replace the old React Router SSR setup with a static SPA build served by
fabro-server, move setup and GitHub auth handling into Rust, and update the
default local web URL and stale Arc-era references to match the Fabro name.
Adopt uv's testing pattern: a shared `fabro-test` crate with TestContext
and fabro_snapshot! macro, plus one test file per subcommand under
tests/it/cmd/. This replaces the trycmd-based tests which were hard to
read and didn't compose well with programmatic assertions.
- Create lib/crates/fabro-test with TestContext, run_and_format,
apply_filters, INSTA_FILTERS, and test_context!/fabro_snapshot! macros
- Add 42 snapshot tests across 16 subcommand files
- Delete trycmd.rs and all tests/cmd/ trycmd files
- Remove trycmd dependency, add fabro-test dev-dependency
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
