## Why

Attendees enter Meeting Assistant from several paths: calendar metadata, accepted recording prompts, workflow actions, screenshot OCR, speaker identity updates, and summarizer add-attendee tools. Today those paths can normalize display names, but they cannot apply local transformation rules such as trimming company suffixes, replacing aliases, or cleaning attendee strings consistently.

## What Changes

- Add an `attendee_added` workflow trigger that runs whenever Meeting Assistant adds an attendee to a meeting note.
- Allow `attendee_added` triggers to filter the added attendee with full equality, substring, or regex matching.
- Expose `attendee.name` to workflow conditions and Razor templates.
- Allow `set_property` to update `attendee.name` during `attendee_added` events, mirroring transcript-line transformation.
- Apply attendee transformations to attendees added by metadata import, prompted-start metadata, workflow `add_attendee`, screenshot OCR, and summary/workflow editor agent tools.

## Impact

- Workflow engine, rules schema validation, and workflow documentation.
- Attendee write paths in recording metadata, screenshot OCR, summary tools, and workflow actions.
- Behavior tests for workflow transformation and representative attendee-add sources.