feat(storybook): add PropertyInspector view for component schema inspection

[geoffjay]

Closes #53

Summary

• New crates/nemo/src/storybook/inspector.rs — PropertyInspector GPUI view
• Reads a component's ConfigSchema from the registry and renders a property table
• Each row shows property name (with * for required), type, default value, and constraints
• inspect(component_name, component_id, cx) method sets the target component and triggers re-render
• set_property() calls runtime.set_component_property() to update the live preview
• mod storybook; added to main.rs

Depends on #52. Part of epic #9.

[geoffjay]

This change is part of the following stack:

• fix(storybook): replace HCL code snippets with XML syntax in styling page #71
  • feat(cli): add nemo storybook subcommand with --component and --search flags #72
    • feat(storybook): add XML config generator crate from component schemas #73
      • feat(storybook): add searchable sidebar and deep-link routing support #74
        • feat(storybook): add PropertyInspector view for component schema inspection #75 ◀

_{Change managed by git-spice.}