Add attendee transformation workflows

docs/meeting-workflow-engine.md

@@ -71,6 +71,12 @@ The engine runs when `MeetingRecordingCoordinator` emits a meeting workflow even
 - `state_transition`: after the assistant context state moves forward.
 - `speaker_identified`: when live or final speaker identification reports a display name.
 - `transcript_line`: after a formatted live transcript line is durably appended, before any changed line is rewritten in place, and before lines are used in full transcript rewrites.
+- `attendee_added`: before a newly added attendee is stored in the meeting note.
+
+`attendee_added` is emitted only by Meeting Assistant code paths that intentionally add an attendee
+through the workflow engine, notification actions, OCR/screenshot processing, summarizer tools, or
+other attendee-add operations. Direct edits to a meeting note file, including direct artifact/frontmatter
+repair writes by an agent, are left verbatim and do not trigger attendee automation.
 
 When a recording is started by accepting a calendar notification, the cached appointment metadata is applied before the `created` event. Rules still receive the normal `created` event and the normal `collecting metadata` to `transcribing` state transition, but they see the accepted appointment title, attendees, agenda, and scheduled end instead of a generated placeholder or a separate Outlook current-meeting lookup result.
 
@@ -162,6 +168,22 @@ on:
       speaker: Guest-1
 ```
 
+### `attendee_added`
+
+Runs before a newly added attendee is stored. `equals`, `contains`, and `regex` filters are optional; omitted filters match any attendee. `equals` and `contains` are case-insensitive.
+
+```yaml
+on:
+  - attendee_added:
+      contains: Contoso
+```
+
+```yaml
+on:
+  - attendee_added:
+      regex: '@contoso\.com>$'
+```
+
 ## Conditions
 
 Conditions use NCalc expressions. Dotted workflow variables may be written directly; the engine rewrites them into NCalc parameters internally.
@@ -184,6 +206,7 @@ Available condition variables:
 - `speaker.name`
 - `transcript.line`
 - `transcript.speaker`
+- `attendee.name`
 
 Available helper functions:
 
@@ -217,6 +240,7 @@ Step `value` fields can be plain strings or Razor templates. Razor templates rec
 - `Model.Speaker.Name`
 - `Model.Transcript.Line`
 - `Model.Transcript.Speaker`
+- `Model.Attendee.Name`
 
 Example:
 
@@ -259,7 +283,11 @@ steps:
 
 ### `set_property`
 
-Sets a supported property. Supported meeting properties are `title` and `meeting.title`. During `transcript_line` events, `transcript.line` is also supported. For live transcription, changing `transcript.line` rewrites the referenced formatted line after the workflow task completes.
+Sets a supported property. Supported meeting properties are `title` and `meeting.title`. During `transcript_line` events, `transcript.line` is also supported. During `attendee_added` events, `attendee.name` is supported. For live transcription, changing `transcript.line` rewrites the referenced formatted line after the workflow task completes. For attendee additions, changing `attendee.name` stores the transformed attendee instead of the original added value.
+
+Rules triggered by `attendee_added` are transformation-only: their steps must use `set_property`
+with `property: attendee.name`. They can still use trigger filters, conditions, and Razor templates
+to decide and compute the transformed value, but they cannot perform note/context side effects.
 
 ```yaml
 steps:
@@ -275,6 +303,13 @@ steps:
     value: '@Model.Transcript.Line.Replace("*****", "[redacted]")'
 ```
 
+```yaml
+steps:
+  - uses: set_property
+    property: attendee.name
+    value: '@Model.Attendee.Name.Replace(" (Contoso)", "")'
+```
+
 ### `add_context`
 
 Appends rendered text to the assistant context artifact body. This step does not count as a meeting-note mutation and does not cause a meeting-note save by itself.
@@ -370,6 +405,20 @@ rules:
       value: '@Model.Transcript.Line.Replace("*****", "[redacted]")'
 ```
 
+Clean attendee names as they are added:
+
+```yaml
+rules:
+- name: clean-contoso-attendees
+  on:
+    - attendee_added:
+        contains: Contoso
+  steps:
+    - uses: set_property
+      property: attendee.name
+      value: '@Model.Attendee.Name.Replace(" (Contoso)", "")'
+```
+
 ## Implementation Notes
 
 Core files: