Add per-leg sights menus; rename yosemite_sights to parks_sights

- Rename yosemite_sights.md -> parks_sights.md, broaden to cover both
  Yosemite and Sequoia/Kings Canyon
- Add sf_sights.md, la_sights.md, vegas_sights.md candidate menus
- Link all sights menus from README and itinerary

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

sf_sights.md

@@ -0,0 +1,34 @@
+# San Francisco — Places to See
+
+*Candidate menu of sights. The chosen, day-by-day version lives in the SF day plans (Sep 20–21) in [`itinerary.md`](itinerary.md).*
+
+> **Getting around:** car for the Marin side (no transit there); BART + cable cars / F-line streetcar for the downtown core (parking is brutal). Base is Daly City, ~20–30 min south.
+
+## Marin side (car only)
+
+- **Marin Headlands / Battery Spencer** — the classic Golden Gate Bridge panorama; go early before fog
+
+## North Waterfront
+
+- **Golden Gate Bridge** — Welcome Center + Fort Point underneath
+- **Lombard Street** — the crooked block
+- **Fisherman's Wharf / Pier 39** — sea lions
+- **Ghirardelli Square** — chocolate + waterfront dining
+- **Coit Tower** — city + bay views from Telegraph Hill
+- **Alcatraz** — ferry from Pier 33, ~2.5–3 hrs round trip. *Book weeks ahead — sells out*
+
+## Downtown / Central
+
+- **Ferry Building** — marketplace, food (big farmers market Tue/Sat)
+- **Cable cars** — California St or Powell lines
+- **Union Square** — shopping core
+- **Chinatown** — Dragon Gate, largest outside Asia
+- **North Beach** — Little Italy, cafés
+
+## West / Parks
+
+- **Alamo Square** — the Painted Ladies
+- **Golden Gate Park** — de Young Museum, Japanese Tea Garden. *de Young closed Mondays*
+- **Lands End** — coastal trail, Sutro Baths ruins
+- **Twin Peaks** — panoramic city viewpoint
+- **Ocean Beach** — Pacific coast, sunsets