scaffold: Backend API routes, DB queries, and middleware stubs

88 handler stubs across 13 route files, 66 DB query stubs across
11 modules, auth/license extractors, and rate limit middleware.
All bodies are todo!() — ready for Phase 1b implementation.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

backend/src/db/stats.rs

@@ -0,0 +1,26 @@
+use sqlx::PgPool;
+use uuid::Uuid;
+use anyhow::Result;
+
+// TODO: Define ServerStats struct (id, server_id, player_count, fps, memory_usage, entities, timestamp)
+// TODO: Define HourlyStats struct (id, server_id, hour, avg_players, avg_fps, avg_memory, peak_players)
+
+/// Insert a raw stats snapshot from the game server.
+pub async fn insert_server_stats(pool: &PgPool, server_id: Uuid, player_count: i32, fps: f64, memory_usage: i64, entities: i32) -> Result<Uuid> {
+    todo!()
+}
+
+/// Get the most recent stats snapshots for a server.
+pub async fn get_recent_stats(pool: &PgPool, server_id: Uuid, limit: i64) -> Result<()> {
+    todo!()
+}
+
+/// Get hourly aggregated stats for charting.
+pub async fn get_hourly_stats(pool: &PgPool, server_id: Uuid, hours: i64) -> Result<()> {
+    todo!()
+}
+
+/// Roll up raw stats into hourly aggregates (called by a scheduled job).
+pub async fn aggregate_hourly_stats(pool: &PgPool, server_id: Uuid) -> Result<()> {
+    todo!()
+}