(chore): document and test new LogLevel APIs

- add godoc for SameLevel and Equal
- update package docs and READMEs with new helpers
- refresh unreleased release notes
- add tests for Printf, HTTP method levels, and level constructors

levels.go

@@ -196,3 +196,50 @@ func (l *LogLevel) GetAttributes() []Attribute {
 	copy(attrs, l.attrs)
 	return attrs
 }
+
+// SameLevel reports whether two log levels have the same severity index.
+func (l *LogLevel) SameLevel(other LogLevel) bool {
+	return l.n == other.n
+}
+
+// Equal reports whether two log levels have identical configuration.
+func (l *LogLevel) Equal(other LogLevel) bool {
+	if l.t != other.t || l.n != other.n {
+		return false
+	}
+	if l.fg != other.fg || l.bg != other.bg {
+		return false
+	}
+
+	if l.fg256 != other.fg256 || l.bg256 != other.bg256 {
+		return false
+	}
+
+	if len(l.attrs) != len(other.attrs) {
+		return false
+	}
+	for i := range l.attrs {
+		if l.attrs[i] != other.attrs[i] {
+			return false
+		}
+	}
+
+	if len(l.fgRgb) != len(other.fgRgb) {
+		return false
+	}
+	for i := range l.fgRgb {
+		if l.fgRgb[i] != other.fgRgb[i] {
+			return false
+		}
+	}
+
+	if len(l.bgRgb) != len(other.bgRgb) {
+		return false
+	}
+	for i := range l.bgRgb {
+		if l.bgRgb[i] != other.bgRgb[i] {
+			return false
+		}
+	}
+	return true
+}