Add component interface view to refrakt inspect

Summary

Extend refrakt inspect to show the component override interface for a rune — what props and slots a component would receive. This makes the contract discoverable from the CLI without reading source code.

Acceptance Criteria

• refrakt inspect <rune> --interface (or similar flag) outputs the component interface
• Output shows property names with their types (string, number, union values)
• Output shows slot names (top-level ref names)
• Output shows which slots are always present vs conditional
• Works for both core and community package runes
• --json flag produces machine-readable output of the interface

Approach

1. After running the identity transform for the inspected rune, call the extraction utility on the output
2. Collect property names from properties keys, types from schema attribute definitions
3. Collect slot names from top-level refs keys
4. Format and display

Resolution

Completed: 2026-04-04

Branch: claude/adr-008-implementation-nBN9K

What was done

• Added --interface flag to packages/cli/src/bin.ts argument parser
• Added showComponentInterface() function in packages/cli/src/commands/inspect.ts
• Added findRuneTag() and findFirstRuneTag() helpers for tree search
• Human-readable output shows Properties, Slots, and Svelte 5 Usage example
• JSON output includes rune name, typeName, properties with types/examples, slots, and hasAnonymousContent
• Updated CLI help text with --interface flag and example

Notes

• Uses the serialized (pre-identity-transform) tree since properties are consumed by the engine
• Falls back to findFirstRuneTag when data-rune doesn't match CLI name (e.g., tabs → tab-group)
• Schema attribute types used for richer type info in output (union literals for enum matches)