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/handler.go

@@ -1,19 +1,23 @@
 package routewatch
 
 import (
+	"git.eeqj.de/sneak/routewatch/internal/logger"
 	"git.eeqj.de/sneak/routewatch/internal/ristypes"
-	"log/slog"
 )
 
 // SimpleHandler is a basic implementation of streamer.MessageHandler
 type SimpleHandler struct {
-	logger       *slog.Logger
+	logger       *logger.Logger
 	messageTypes []string
 	callback     func(*ristypes.RISMessage)
 }
 
 // NewSimpleHandler creates a handler that accepts specific message types
-func NewSimpleHandler(logger *slog.Logger, messageTypes []string, callback func(*ristypes.RISMessage)) *SimpleHandler {
+func NewSimpleHandler(
+	logger *logger.Logger,
+	messageTypes []string,
+	callback func(*ristypes.RISMessage),
+) *SimpleHandler {
 	return &SimpleHandler{
 		logger:       logger,
 		messageTypes: messageTypes,