Move --storage-dir and --server-url off GlobalArgs and onto the
leaf commands that actually honor them.
This aligns help, parser behavior, and env-var wiring with the
current command architecture while preserving the intended model
and exec targeting semantics.
The server subcommand and related code were gated behind
cfg(feature = "server"). This removes the feature flag entirely,
making fabro-server a required dependency so the server command
is always available.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
