Inject Config as dependency for database, routing table, and snapshotter

- Remove old database Config struct and related functions
- Update database.New() to accept config.Config parameter
- Update routingtable.New() to accept config.Config parameter
- Update snapshotter.New() to accept config.Config parameter
- Simplify fx module providers in app.go
- Fix truthiness check for environment variables
- Handle empty state directory gracefully in routing table and snapshotter
- Update all tests to use empty state directory for testing

internal/routewatch/app_integration_test.go

@@ -7,6 +7,7 @@ import (
 	"testing"
 	"time"
 
+	"git.eeqj.de/sneak/routewatch/internal/config"
 	"git.eeqj.de/sneak/routewatch/internal/database"
 	"git.eeqj.de/sneak/routewatch/internal/metrics"
 	"git.eeqj.de/sneak/routewatch/internal/routingtable"
@@ -171,8 +172,14 @@ func TestRouteWatchLiveFeed(t *testing.T) {
 	// Create streamer
 	s := streamer.New(logger, metricsTracker)
 
+	// Create test config with empty state dir (no snapshot loading)
+	cfg := &config.Config{
+		StateDir:   "",
+		MaxRuntime: 5 * time.Second,
+	}
+
 	// Create routing table
-	rt := routingtable.New(logger)
+	rt := routingtable.New(cfg, logger)
 
 	// Create server
 	srv := server.New(mockDB, rt, s, logger)
@@ -184,9 +191,7 @@ func TestRouteWatchLiveFeed(t *testing.T) {
 		Streamer:     s,
 		Server:       srv,
 		Logger:       logger,
-		Config: Config{
-			MaxRuntime: 5 * time.Second,
-		},
+		Config:       cfg,
 	}
 	rw := New(deps)