itinerary: split day plans into days/, plan SF Sep 21

- One file per day under days/; timeline table reduced to date, weekday, place
- Sep 19–20: KT & VT Uber to Airbnb, rest day; LK & MS drive rental to Airbnb
- Sep 21: Silicon Valley morning, optional Twin Peaks / Painted Ladies /
  Lands End, Battery Spencer at sunset
- LK Hertz LAX rental marked not available for planning; LA / San Diego
  hotels cancelled
- sf_sights: add Silicon Valley and Mission / Castro, skip Computer History
  Museum

Claude-Session: https://claude.ai/code/session_01CWLR7htYGAB9i89P8jCCLn

days/2026-09-19.md

@@ -0,0 +1,12 @@
+# Sep 19 (Sat) — San Francisco — KT & VT arrive
+
+**Stay:** [Airbnb — Daly City](../bookings/stays/airbnb-sf-daly-city.md) · check-in after 3 PM
+
+## Logistics
+
+- KT & VT land SFO 1 PM ([flights](../bookings/transport/flights-kt-vt.md)) · Uber to the Airbnb
+- ⚠️ Confirm they can check in without MS; make sure they get the host's check-in instructions (sent ~Sep 16)
+
+## Plan
+
+- Rest day (jet lag)