feat: Sentinela v0.2.0 — Brazilian Financial Data API in Go

- 20 Go source files, single 16MB binary
- SQLite + FTS5 full-text search (pure Go, no CGO)
- BCB integration: Selic, CDI, IPCA, USD/BRL, EUR/BRL
- CVM integration: 2,524 companies from registry
- Fiber v2 REST API with 42 handlers
- Auto-seeds on first run (~5s for BCB + CVM)
- Token bucket rate limiter, optional API key auth
- Periodic sync scheduler (configurable)
- Graceful shutdown, structured logging (slog)
- All endpoints tested with real data

internal/fetcher/scheduler.go

@@ -0,0 +1,28 @@
+package fetcher
+
+import (
+	"log/slog"
+	"time"
+
+	"github.com/sentinela-go/internal/db"
+)
+
+func StartScheduler(database *db.DB, interval time.Duration, stop <-chan struct{}) {
+	ticker := time.NewTicker(interval)
+	defer ticker.Stop()
+
+	for {
+		select {
+		case <-ticker.C:
+			slog.Info("scheduled sync starting")
+			if err := FetchAllBCB(database); err != nil {
+				slog.Error("scheduled BCB sync failed", "error", err)
+			}
+			if err := FetchAllCVM(database); err != nil {
+				slog.Error("scheduled CVM sync failed", "error", err)
+			}
+		case <-stop:
+			return
+		}
+	}
+}