feat(go-config): multi-format codecs, envc CLI, fixtures, ASRs

- Module github.com/eslider/go-config with env/yaml/json/ini packages
- internal: source, keymap, merge, structconv, bytesutil
- cmd/envc: convert, get, merge
- docs/asr ASR-0001..0008, README/CHANGELOG/AGENTS refresh
- golangci-lint v2 config; tests + fixtures

Co-authored-by: Cursor <cursoragent@cursor.com>

ini/map_flat.go

@@ -0,0 +1,49 @@
+package ini
+
+import (
+	"strings"
+
+	iniv1 "gopkg.in/ini.v1"
+)
+
+func insertPath(root map[string]any, path []string, value string) {
+	current := root
+	last := len(path) - 1
+	for i, raw := range path {
+		k := strings.ToLower(raw)
+		if i == last {
+			if _, exists := current[k]; exists {
+				return
+			}
+			current[k] = value
+			return
+		}
+		next, ok := current[k].(map[string]any)
+		if !ok {
+			next = make(map[string]any)
+			current[k] = next
+		}
+		current = next
+	}
+}
+
+func mapFromINIFile(f *iniv1.File) map[string]any {
+	out := make(map[string]any)
+	for _, name := range f.SectionStrings() {
+		sec, err := f.GetSection(name)
+		if err != nil {
+			continue
+		}
+		if strings.EqualFold(name, iniv1.DefaultSection) {
+			for k, v := range sec.KeysHash() {
+				insertPath(out, []string{k}, v)
+			}
+			continue
+		}
+		path := strings.Split(name, ".")
+		for k, v := range sec.KeysHash() {
+			insertPath(out, append(append([]string{}, path...), k), v)
+		}
+	}
+	return out
+}