[tony]

Summary

libtmux.org shows a preset picker on a port's Workspace Manager pages only when the port's repository loads more than one workspace file in a test. This port loaded one. This PR adds tmuxp's example catalog as fixtures under test/fixtures/tmuxp/, with tmuxp's MIT license, copied from libtmux-rs at ab33c91, and loads every file through LibTmux::Workspace.load in test/unit/workspace_test.rb, as Rust's every_tmuxp_example_parses does. Nothing in the loader changes.

Nine of the 23 files load. The other 14 are kept and recorded with the exact error the loader raises, so a loader change fails the case until the entry is updated or removed. A catalog file in neither list also fails, so a new tmuxp example gets classified.

Closes #101
Part of libtmux/docs#282

Findings: files the loader refuses

File	Error (LibTmux::Workspace::ConfigError)
2-pane-synchronized.yaml	invalid workspace configuration at $.windows[0]; expected supported data-only fields; move callbacks or hooks into explicit application code
blank-panes.yaml	invalid workspace configuration at $.windows[0].panes[0]; expected configuration object
env-variables.yaml	invalid workspace configuration at $.before_script; expected supported data-only fields; move callbacks or hooks into explicit application code
main-pane-height-percentage.yaml	invalid workspace configuration at $.windows[0].options.main-pane-height; expected integer index from zero through 2147483647
minimal.yaml	invalid workspace configuration at $.windows[0].window_name; expected window name
options.yaml	invalid workspace configuration at $; expected supported data-only fields; move callbacks or hooks into explicit application code
pane-shell.yaml	invalid workspace configuration at $.windows[0]; expected supported data-only fields; move callbacks or hooks into explicit application code
plugin-system.yaml	invalid workspace configuration at $.plugins; expected supported data-only fields; move callbacks or hooks into explicit application code
skip-send-pane-level.yaml	invalid workspace configuration at $.windows[0].window_name; expected window name
skip-send.yaml	invalid workspace configuration at $.windows[0].window_name; expected window name
sleep-pane-level.yaml	invalid workspace configuration at $.windows[0].window_name; expected window name
sleep-virtualenv.yaml	invalid workspace configuration at $.shell_command_before; expected UTF-8 text
sleep.yaml	invalid workspace configuration at $.windows[0].window_name; expected window name
suppress-history.yaml	invalid workspace configuration at $; expected supported data-only fields; move callbacks or hooks into explicit application code

main-pane-height.yaml, start-directory.yaml and focus-window-and-panes.yaml load, but the docs support table marks them unsupported because the loader reads their ~ paths and bare pane entries differently from tmuxp. The docs generator refuses to show them until that table agrees.

Test plan

• bundle exec ruby test/unit/workspace_test.rb
• bundle exec scripts/check mid
• Changing a recorded message and removing a loaded file from its list each fail the test
• The docs generator (scripts/gen-workspace-showcase.mjs) run at libtmux/docs main with the port pinned to this branch lists seven examples for ruby, six of them tmuxp's files, each tested by test_tmuxp_examples_load_through_workspace_load
• CI