feat: integrate plugins into core runtime

[prosdev]

Implements Issue #9 - Integrate Plugins into Core

Changes

• Auto-register storage, debug, frequency, and banner plugins in ExperienceRuntime constructor
• Move shared types to plugins package to resolve circular dependency
• Update core to depend on plugins package (proper dependency direction)
• Bundle all dependencies in IIFE build for script tag usage
• Remove default export to fix rollup named/default export warning
• Configure Biome to allow any in specs contracts
• Update pre-commit hook to match sdk-kit pattern (only lint staged files)

Technical Details

Circular Dependency Resolution

• Created with shared type definitions
• Plugins no longer depend on core
• Core imports types and implementations from plugins

Build Configuration

• Core bundles: @lytics/sdk-kit, @lytics/sdk-kit-plugins, @prosdevlab/experience-sdk-plugins
• Pre-commit builds packages before typecheck (needed for workspace deps)
• Dist files cleaned up after pre-commit checks

Testing

• All 120 tests passing
• Build successful (ESM + IIFE)
• Typecheck passing
• Linter clean

Closes #9