feat: load explicit configuration references and remove implicit env overlays

config/suggestions.go

@@ -0,0 +1,51 @@
+package config
+
+import (
+	"reflect"
+	"strconv"
+	"strings"
+)
+
+// Suggest only a unique, nearby declared field. Input values are never used.
+func unknownFieldReason(name string, fields map[string]reflect.StructField) string {
+	if len(name) < 3 || len(name) > 128 {
+		return "unknown field"
+	}
+	best, match, tied := 3, "", false
+	for candidate := range fields {
+		if len(candidate) > 128 {
+			continue
+		}
+		d := fieldDistance(strings.ToLower(name), strings.ToLower(candidate))
+		if d < best {
+			best, match, tied = d, candidate, false
+		} else if d == best {
+			tied = true
+		}
+	}
+	if match != "" && !tied && best <= 2 {
+		return "unknown field; did you mean " + strconv.Quote(match) + "?"
+	}
+	return "unknown field"
+}
+func fieldDistance(a, b string) int {
+	prev := make([]int, len(b)+1)
+	for i := range prev {
+		prev[i] = i
+	}
+	for i := 0; i < len(a); i++ {
+		left, diagonal := i+1, prev[0]
+		prev[0] = left
+		for j := 0; j < len(b); j++ {
+			cost := 0
+			if a[i] != b[j] {
+				cost = 1
+			}
+			old := prev[j+1]
+			left = min(left+1, old+1, diagonal+cost)
+			prev[j+1] = left
+			diagonal = old
+		}
+	}
+	return prev[len(b)]
+}