feat: 配置列表分页与钉钉机器人分钟级排队限流

统一 sources/templates/channels/rules 列表为分页响应，避免配置增多时全量返回；按钉钉 access_token 限制每分钟发送并在超限时等待下一分钟，降低触发官方封禁风险。

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

internal/store/page_test.go

@@ -0,0 +1,30 @@
+package store
+
+import "testing"
+
+func TestPageFilterNormalize(t *testing.T) {
+	tests := []struct {
+		name         string
+		in           PageFilter
+		wantPage     int
+		wantPageSize int
+		wantOffset   int
+	}{
+		{name: "defaults", in: PageFilter{}, wantPage: 1, wantPageSize: 20, wantOffset: 0},
+		{name: "negative", in: PageFilter{Page: -1, PageSize: -5}, wantPage: 1, wantPageSize: 20, wantOffset: 0},
+		{name: "page2", in: PageFilter{Page: 2, PageSize: 10}, wantPage: 2, wantPageSize: 10, wantOffset: 10},
+		{name: "zero page size", in: PageFilter{Page: 3, PageSize: 0}, wantPage: 3, wantPageSize: 20, wantOffset: 40},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			p := tt.in
+			p.Normalize()
+			if p.Page != tt.wantPage || p.PageSize != tt.wantPageSize {
+				t.Fatalf("Normalize() = %+v, want page=%d page_size=%d", p, tt.wantPage, tt.wantPageSize)
+			}
+			if got := p.Offset(); got != tt.wantOffset {
+				t.Fatalf("Offset() = %d, want %d", got, tt.wantOffset)
+			}
+		})
+	}
+}