feat: add Solon to Chagrin Falls Trail

[fatherlinux]

Summary

• Adds the Solon to Chagrin Falls Trail as a trail POI with full OSM geometry (19 segments, 220 points)
• Multi-use rail-trail on former W&LE/NKP railroad corridor connecting Solon and Chagrin Falls
• Phase 1 (Solon section) opened October 2025; Phase 2 (floodplain bridge) under construction 2026
• Activities: Biking, Hiking, Horseback Riding

Gatehouse Review Notes

• HIGH (false positive): primary_activities is a text column, not an array — all existing trail migrations use the same comma-separated string format
• MEDIUM (moot): WHERE NOT EXISTS is a standard idempotency guard for one-time migrations

Test plan

• Migration applies cleanly (verified in dev container, POI 6363)
• Trail renders on map in Solon/Chagrin Falls area
• Gap over Aurora Branch floodplain accurately reflects unbuilt Phase 2 section
• ./run.sh test passes (Gourmand violations are pre-existing data/boundaries scripts)

🤖 Generated with Claude Code

[gemini-code-assist]

Code Review

This pull request introduces a new database migration (078_add_solon_chagrin_falls_trail.sql) that inserts a new trail Point of Interest (POI) for the 'Solon to Chagrin Falls Trail' into the pois table, including its geographic coordinates, description, and geometry. There are no review comments, and the changes look correct, so I have no feedback to provide.