docs: point the two brand parsers at each other

Removing extension's dependency on internal left the brand rule implemented
twice, once per Brand type. The two cannot share code: extension is published
as a standalone SDK and may not import internal, which is the constraint this
branch exists to establish. Cross-reference them so a third brand is added to
both rather than to whichever one the next author happens to open.

Also correct the timestamp wrapper's comment, which has claimed "HH:mm" since
before this branch while every implementation formatted seconds too.

extension/credential/types.go

@@ -20,6 +20,11 @@ const (
 // It lives next to the Brand constants so every credential source resolves the
 // brand the same way; duplicating the rule per provider would let one copy
 // drift when the brand set changes.
+//
+// internal/core.ParseBrand applies the same rule to core.LarkBrand, which the
+// rest of the CLI uses. The two cannot share an implementation: this package is
+// published as a standalone SDK and may not import internal. Adding a brand
+// means changing both.
 func ParseBrand(value string) Brand {
 	if strings.ToLower(strings.TrimSpace(value)) == string(BrandLark) {
 		return BrandLark

internal/core/types.go

@@ -17,6 +17,10 @@ const (
 
 // ParseBrand normalizes a brand string (case-insensitive, whitespace-tolerant);
 // anything other than "lark" normalizes to BrandFeishu.
+//
+// extension/credential.ParseBrand applies the same rule to its own Brand type.
+// The two cannot share an implementation: extension is published as a standalone
+// SDK and may not import internal. Adding a brand means changing both.
 func ParseBrand(value string) LarkBrand {
 	if strings.ToLower(strings.TrimSpace(value)) == "lark" {
 		return BrandLark

shortcuts/im/convert_lib/helpers.go

@@ -24,7 +24,7 @@ func ResolveMentionKeys(text string, mentionMap map[string]string) string {
 }
 
 // formatTimestamp converts a Unix timestamp string (seconds or milliseconds) to
-// "YYYY-MM-DD HH:mm" local time. Values with fewer than 10 digits are treated as
+// "YYYY-MM-DD HH:mm:ss" local time. Values with fewer than 10 digits are treated as
 // seconds; larger values are treated as milliseconds.
 // Returns empty string if the input is empty or unparseable.
 func formatTimestamp(ts string) string {