Replaces flat star_systems table with 7 normalized tables: star_systems,
system_gates (with hop_distance_from_gateway), system_history,
historical_events (1:N), system_economy, system_factions, system_culture.
Primary key is now the GJ astronomical ID (e.g., "GJ 244A") — S-number
identifiers removed entirely. The astronomical_id column is dropped as
redundant. Database moved to server/data/systems.db (ships with game).
10 core systems fully populated with structured data.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>