Implement Event Emitter Capability

[prosdev]

📋 Spec: specs/phase-1-core-sdk/tasks.md#task-2

Implement event emitter with wildcard support using regex pattern matching.

Files to create:

• packages/core/src/capabilities/emitter.ts
• packages/core/src/capabilities/emitter.test.ts

Implementation:

• Use regex compilation for wildcard patterns
• Return unsubscribe function from on()
• Support patterns: widget.*, *.show, *

Acceptance Criteria:

• Wildcard patterns work correctly
• Unsubscribe function works
• Test coverage > 90% (achieved 100%)
• No memory leaks

Depends on: #1
Blocks: #6

Can run in parallel: Yes [P]