calendar: remove self-notification emails (CalDAV sync replaces them)

Remove three redundant email flows since all devices sync via CalDAV:
- Auto-adding mail@luyx.org as attendee on outgoing invites
- Forwarding invites to mail@luyx.org on accept/tentative
- Emailing todos to mail@luyx.org on todo add

skills/calendar/TESTING.md

@@ -16,7 +16,7 @@ TEST_DATE=$(date -d "+3 days" +%Y-%m-%d)
 Generates the ICS and MIME email without sending. Check that:
 - ICS has `METHOD:REQUEST`
 - MIME has `Content-Type: text/calendar; method=REQUEST`
-- `mail@luyx.org` appears as attendee (auto-added)
+- Only `--to` recipients appear as attendees
 - Times and timezone look correct
 
 ```bash
@@ -89,8 +89,7 @@ $SKILL_DIR/scripts/calendar.sh reply \
 
 **Verify:**
 - [ ] Reply sent to organizer (youlu@luyanxin.com, i.e. ourselves)
-- [ ] Original invite forwarded to `mail@luyx.org`
-- [ ] Event still in `~/.openclaw/workspace/calendars/home/`
+- [ ] Event saved to `~/.openclaw/workspace/calendars/home/`
 - [ ] `vdirsyncer sync` ran
 - [ ] `khal list "$TEST_DATE"` still shows the event
 
@@ -119,7 +118,6 @@ $SKILL_DIR/scripts/calendar.sh reply \
 
 **Verify:**
 - [ ] Reply sent to organizer with comment
-- [ ] Event NOT forwarded to `mail@luyx.org`
 - [ ] Event removed from local calendar
 - [ ] `khal list "$TEST_DATE"` does NOT show "Decline Test Event"
 
@@ -142,12 +140,11 @@ khal list today 7d
 
 ## 7. Dry Run: Add Todo
 
-Generates the VTODO ICS and MIME email without saving. Check that:
+Generates the VTODO ICS without saving. Check that:
 - ICS has `BEGIN:VTODO`
 - ICS has correct `PRIORITY` value (1 for high)
 - ICS has `STATUS:NEEDS-ACTION`
 - ICS has `BEGIN:VALARM`
-- MIME has `Content-Type: text/calendar`
 
 ```bash
 $SKILL_DIR/scripts/calendar.sh todo add \
@@ -171,7 +168,6 @@ $SKILL_DIR/scripts/calendar.sh todo add \
 - [ ] Script exits without error
 - [ ] `.ics` file created in `~/.openclaw/workspace/calendars/tasks/`
 - [ ] `todo list` (todoman directly) shows "Test Todo"
-- [ ] Email arrives at `mail@luyx.org` with .ics attachment
 - [ ] `vdirsyncer sync` ran
 
 ## 9. List Todos