fix: fuzzy project resolution and guard against accidental project creation

- _resolve_project now uses reverse-substring + SequenceMatcher (≥0.55)
  so partial names like "Famous Supply" match "Famous Supply Co." reliably
- create_project runs similar-project checks before the confirmed gate so
  confirmed=true can't bypass them; threshold lowered to 0.55 to catch
  abbreviated names
- Error messages on project-not-found no longer suggest create_project,
  directing the model to list_projects first
- Tool description updated to explicitly prohibit calling create_project
  in response to a lookup failure
- tasks.py: fire-and-forget embedding update on create/update
- briefing_pipeline.py: await is_caldav_configured (was sync call)
- notes.py: remove erroneous duplicate count_query filter

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/fabledassistant/services/briefing_pipeline.py

@@ -80,7 +80,7 @@ async def _gather_internal(user_id: int) -> dict:
     # Calendar events today
     calendar_events = []
     try:
-        if is_caldav_configured(user_id):
+        if await is_caldav_configured(user_id):
             events = await list_events(user_id, start=today, end=today)
             calendar_events = [
                 f"{e.get('summary', 'Event')} at {e.get('dtstart', 'unknown time')}"