docs: add example programs for common usage patterns (#19)

Adds four focused examples in examples/ directory:
- basic: drop-in logger with web UI
- namespaces: namespace-based logging by component
- client: programmatic log client with filtering
- log-levels: all log levels and filtering

Fixes #7

examples/log-levels/main.go

@@ -0,0 +1,48 @@
+// Example: log level filtering and all available levels.
+//
+// log-socket supports 8 log levels from TRACE (most verbose)
+// to FATAL (least verbose). Setting a log level filters out
+// everything below it.
+package main
+
+import (
+	"fmt"
+
+	logger "github.com/taigrr/log-socket/v2/log"
+)
+
+func main() {
+	defer logger.Flush()
+
+	fmt.Println("=== All log levels (TRACE and above) ===")
+	logger.SetLogLevel(logger.LTrace)
+
+	logger.Trace("Detailed execution trace — variable x = 42")
+	logger.Debug("Processing request for user_id=123")
+	logger.Info("Server started on :8080")
+	logger.Notice("Configuration reloaded")
+	logger.Warn("Disk usage at 85%")
+	logger.Error("Failed to send email: SMTP timeout")
+	// logger.Panic("...") — would panic
+	// logger.Fatal("...") — would os.Exit(1)
+
+	fmt.Println("\n=== Formatted variants ===")
+	logger.Infof("Request took %dms", 42)
+	logger.Warnf("Retrying in %d seconds (attempt %d/%d)", 5, 2, 3)
+	logger.Errorf("HTTP %d: %s", 503, "Service Unavailable")
+
+	fmt.Println("\n=== Only WARN and above ===")
+	logger.SetLogLevel(logger.LWarn)
+
+	logger.Debug("This will NOT appear")
+	logger.Info("This will NOT appear either")
+	logger.Warn("This WILL appear")
+	logger.Error("This WILL appear too")
+
+	fmt.Println("\n=== Per-logger levels via namespaced loggers ===")
+	logger.SetLogLevel(logger.LTrace) // Reset global
+
+	appLog := logger.NewLogger("app")
+	appLog.Info("Namespaced loggers inherit the global output but tag entries")
+	appLog.Warnf("Something needs attention in the %s subsystem", "app")
+}