Update minimum go version to 1.26.1, golangci-lint to 2.11.2, fix test style (#36876)

Hey, I bumped Go to 1.26.1 and fixed a couple of things I ran into while
poking around.

### Changes

- Bump go.mod from 1.26.0 to 1.26.1 (security patch)
- Bump golangci-lint from v2.10.1 to v2.11.2
- Run make tidy, fmt, lint-go

---------

Co-authored-by: silverwind <me@silverwind.io>
Co-authored-by: Claude (Opus 4.6) <noreply@anthropic.com>

tests/integration/repo_test.go

@@ -92,9 +92,10 @@ func testViewRepoWithCache(t *testing.T) {
 			tds := s.Find(".repo-file-cell")
 			var f file
 			tds.Each(func(i int, s *goquery.Selection) {
-				if i == 0 {
+				switch i {
+				case 0:
 					f.fileName = strings.TrimSpace(s.Text())
-				} else if i == 1 {
+				case 1:
 					a := s.Find("a")
 					f.commitMsg = strings.TrimSpace(a.Text())
 					l, _ := a.Attr("href")