Coastline analysis and fix:
- Coastlines now only show 2-edge patterns (straight, wide curve,
sharp bend) — Y-junctions and crossroads removed since a coast
always divides exactly two sides
- Added waterSide property to HexFeature (1=CW, -1=CCW) — stored
explicitly instead of computed by broken center-distance heuristic
that flipped water/land at rotation midpoint
- F key or "Flip water side" button in palette to toggle which side
is water before placing
- Inspector shows flip button (swap arrows) for placed coastlines
- Rotation preserves waterSide — no more land/water swaps
- Separate pattern lists: GENERAL_PATTERNS for road/river,
COASTLINE_PATTERNS for coastline (core/tile-patterns.ts)
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
ce95930b87