Validate property and ref name uniqueness in createComponentRenderable

Summary

Add a static validation step to createComponentRenderable that checks for naming collisions between properties keys and refs keys. Since ADR-008 uses a flat namespace where both properties and refs become component props/slots, duplicate names would cause silent overwrites.

Acceptance Criteria

• createComponentRenderable throws a descriptive error if any key appears in both properties and refs
• Error message includes the rune name and the colliding key(s)
• All existing runes pass validation (no current collisions)
• Unit test for collision detection
• Unit test confirming no false positives on valid runes

Approach

1. In packages/runes/src/lib/component.ts, add a Set intersection check between Object.keys(properties) and Object.keys(refs) before building the renderable
2. Throw with rune name and colliding keys if intersection is non-empty

Resolution

Completed: 2026-04-04

Branch: claude/adr-008-implementation-nBN9K

What was done

• Added Set intersection validation in packages/runes/src/lib/component.ts
• Fixed 3 pre-existing collisions: bento-cell icon (renamed property to iconSource), faction/realm name (removed from properties, kept as ref only)
• 9 unit tests in packages/runes/test/component.test.ts

Notes

• Validation runs before attribute decoration, catching collisions at build time
• All 1969 existing tests pass after fixing the 3 collisions