feat: SSR 评论编辑与作者删除

帖详情提供时限内编辑与软删入口，作者删除与管理员共用回收站子树语义。

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

services/comment_edit_test.go

@@ -0,0 +1,47 @@
+package services
+
+import (
+	"testing"
+	"time"
+
+	"git.iioio.com/freefire/jiang13-forum/models"
+)
+
+func TestCanEditComment(t *testing.T) {
+	now := time.Now()
+	c := &models.Comment{UserID: 7, CreatedAt: now}
+	if !canEditComment(c, 7, false, 3) {
+		t.Fatal("author within window")
+	}
+	if canEditComment(c, 8, false, 3) {
+		t.Fatal("other user")
+	}
+	if !canEditComment(c, 1, true, 3) {
+		t.Fatal("admin always")
+	}
+	old := &models.Comment{UserID: 7, CreatedAt: now.Add(-10 * time.Minute)}
+	if canEditComment(old, 7, false, 3) {
+		t.Fatal("expired")
+	}
+	if !canEditComment(old, 7, true, 3) {
+		t.Fatal("admin ignores window")
+	}
+}
+
+func TestCanUserDeleteComment(t *testing.T) {
+	s := &CommentService{}
+	c := &models.Comment{UserID: 3}
+	if !s.CanUserDeleteComment(c, 3, false) {
+		t.Fatal("author")
+	}
+	if s.CanUserDeleteComment(c, 4, false) {
+		t.Fatal("other")
+	}
+	if !s.CanUserDeleteComment(c, 1, true) {
+		t.Fatal("admin")
+	}
+	guest := &models.Comment{UserID: 0}
+	if s.CanUserDeleteComment(guest, 1, false) {
+		t.Fatal("guest author id 0")
+	}
+}