Add custom logger with source location tracking and remove verbose database logs

- Create internal/logger package with Logger wrapper around slog
- Logger automatically adds source file, line number, and function name to all log entries
- Use golang.org/x/term to properly detect if stdout is a terminal
- Replace all slog.Logger usage with logger.Logger throughout the codebase
- Remove verbose logging from database GetStats() method
- Update all constructors and dependencies to use the new logger

internal/routewatch/app_integration_test.go

@@ -9,6 +9,7 @@ import (
 
 	"git.eeqj.de/sneak/routewatch/internal/config"
 	"git.eeqj.de/sneak/routewatch/internal/database"
+	"git.eeqj.de/sneak/routewatch/internal/logger"
 	"git.eeqj.de/sneak/routewatch/internal/metrics"
 	"git.eeqj.de/sneak/routewatch/internal/routingtable"
 	"git.eeqj.de/sneak/routewatch/internal/server"
@@ -164,7 +165,7 @@ func TestRouteWatchLiveFeed(t *testing.T) {
 	mockDB := newMockStore()
 	defer mockDB.Close()
 
-	logger := NewLogger()
+	logger := logger.New()
 
 	// Create metrics tracker
 	metricsTracker := metrics.New()