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/2026-09-21.md

@@ -0,0 +1,25 @@
+# Sep 21 (Mon) — San Francisco
+
+**Stay:** [Airbnb — Daly City](../bookings/stays/airbnb-sf-daly-city.md)
+
+## Plan
+
+> Menu: [`sf_sights.md`](../sf_sights.md). Items below are agreed; everything else is still on the menu.
+
+- **~8:30 AM** Drive south to Silicon Valley (~45 min)
+- **9 AM** Apple Park Visitor Center, Cupertino — rooftop terrace over the ring, AR campus model, store
+- **Late morning** Google Visitor Experience, Mountain View (15 min) — optional Stanford campus walk after
+- **~1–2 PM** Drive back north on I-280; stops below are optional, in route order
+- *Optional:* Twin Peaks — city panorama, 15-min stop, right off I-280. Navigate to [Christmas Tree Point](https://www.google.com/maps/search/Christmas+Tree+Point+San+Francisco)
+- *Optional:* Painted Ladies — 10 min north-east; short stop at Alamo Square
+- *Optional:* Lands End — 20 min west via Geary; Sutro Baths ruins + coastal trail (~45 min short version), Ocean Beach next door. Park at [Lands End Lookout](https://www.google.com/maps/search/Lands+End+Lookout+San+Francisco)
+- **~5:45 PM** Drive over the Golden Gate Bridge to Marin (20–25 min from Lands End in commute traffic)
+- **Sunset (~7:08 PM)** Marin Headlands / Battery Spencer — Golden Gate Bridge panorama (car). Navigate to the [parking lot](https://maps.app.goo.gl/EyUVPs1X9CACtqMa9), 3-min walk up. Small lot: arrive by ~6:15 PM. Stay for blue hour. Windy and cold — jackets
+
+## Notes
+
+- **Alcatraz** — ferry from Pier 33, ~2.5–3 hrs, no car needed. Sells out weeks ahead — reserve early if wanted
+- **Monday:** some museums (incl. the de Young, Computer History Museum) are closed
+- Verify Apple / Google visitor center hours before going
+- Bridge toll is electronic, southbound only (on the way back). SIXT bills it with a fee unless a toll pass is added at pickup
+- If the Battery Spencer lot is full: shoulder parking up Conzelman Rd, or Hawk Hill 5 min further